Feature: Benjamin Banneker

This entry is part 1 of 8 in the series June 2014

Benjamin Banneker is arguably the most prominent figure in Baltimore area land survey history, and this biography details some of its highlights.

By Eddie Glawe

Early Life

Banneker1This dramatic story begins with Molly Welsh (may have been Walsh), Benjamin’s grandmother, a young servant or milk maid in England. As she was doing her work, a pail of milk was spilled. She was consequently considered to have stolen it, and was arrested. Felony charges at the time allowed the convicted party to “call for the book.” This involved demonstrating the ability to read and speak aloud some bit of writing to prove literacy, thus reducing a capital punishment to the branding of the thumb. It is believed that after she demonstrated her ability she was shipped to the colonies to provide plantation labor rather than being executed.

After a horrible ordeal of a convict’s conditions in a transatlantic trip, she was believed to have been sold at a Chesapeake Bay slave market. As a consequence, she served a seven year indenture. Once this was completed, she was granted her freedom and rented a small farm near the confluence of the Patapsco River and Cooper’s Branch, now known as Oella, Maryland.

Although her small farm was in the midst of the wilderness, she worked to clear the land for planting corn and tobacco. After some years, she had accrued enough income to purchase labor in assistance on the farm. Her new purchase consisted of two slaves from one of the “soul drivers” or “soul agents” that frequented the rolling roads. Although it can be expected she was opposed to slavery, this decision could have been by necessity. A “rolling road,” at the time, was a route for the local tobacco farmers to move their hogsheads of packed tobacco to port. A hogshead was a barrel used to both store and transport tobacco, among other commodities. Hogsheads at the time were 4 feet long and 30 inches greatest diameter. A tobacco hogshead had an axle through it, making it a wheel. When packed with tobacco, it weighed in at about a thousand pounds.

In time, her expectation of the first slave was realized, and her apprehension of the other was as well. The “strong” slave was robust, clever, and adaptable (record of his name has not survived). The other slave provided good social company to her, his name was Bannka, Banneka, Banneky, or Bannaka. He claimed to have been of Senegambian royal lineage.

Banneker2After six years of work for Molly Welsh, she granted the two of them their freedom. She then marries Bannka, a risky act considering the political climate in Maryland at the time. In 1661, the following statute was recorded:

“And forasmuch as divers freeborn English women, forgetful of their free condition, and to the disgrace of our nation, do intermarry with negro slaves, by which also divers suits may arise, touching the issue of such women, and great damage doth befall the master of such negroes, for preservation whereof for deterring such free-born women from such shameful matches, be it enacted, That whatsoever free-born woman shall intermarry with any slave, and after the last day of the present assembly, shall serve the master of such slave during the life of    her husband; and that all the issues of such free-born women, so married, shall be slaves as their fathers were….And it be further enacted, That all the issues of the   English, or other free-born women, that have already married negroes, shall serve the master of their parents, till they be thirty years of age and no longer”

Other new statutes ensued. In 1681 it was illegal in the state for any minister to join in marriage any “Negro and white woman servant free-born.” In 1684, any free-born woman who married a negro or bore his child forfeited her freedom and became a servant “to the minister of the Poor of the same Parish.” About 30 years later than that, the laws provided severe punishment for any white man or woman who cohabited with a Negro, free or slave.

Molly Welsh married the former slave anyway, and took his name. Possibly the fact that they resided in near wilderness provided some insulation from the law. They continued to live on the small farm, and raised their four daughters, Mary, Katherine, Esther, and Jemima.

Mary, Benjamin’s mother, married Robert, an emigrant Guinean who had been captured and sold into slavery. Records indicate he only served a seven-year indenture to regain his freedom.  They also show that he had been given the name Robert upon baptism at the time of his newfound freedom. When he married Mary he had no family name, so he took Banneky as his. Mary gave birth to Benjamin first, on November 9, 1731. Their second child had no recorded name, and then they had Jemima, Minta, and Molly, all while sharing the small farm with Molly Welsh.

In what seems to be the cleverest decision on young Benjamin’s behalf, Molly Welsh recorded an indenture with Richard Gist, a wealthy landowner in Baltimore County. For the sum of seven thousand pounds of tobacco, she secured the land, in a recorded agreement, to both Robert and Benjamin. At six years of age, young Benjamin was sitting at the settlement table with his father, signing for his freedom and his farm, across from the deputy surveyor of the western shore of Maryland, Gist. This also guaranteed their freedom, and the freedom of future generations, by virtue of being landowners. Quite a feat, considering Benjamin was a product of two generations of mixed race parents, crimes in their day. This indenture (mortgage) was written as follows:

“Richard Gist                                                                                      1737

Robert Bannaky
Benjamin Bannaky

This indenture made this tenth day of March in the year of our Lord one thousand seven hundred thirty seven between Richard Gist of Baltimore County in the province of Maryland grant of the one part, Robert Bannaky and Benjamin Bannaky this now of the County and province aforementioned of the other part, Witnesseth that the deed Richard Gist for and in consideration of the sum of seven thousand pounds of tobacco whence paid to the said Richard Gist the receipt whereof he do able by these presents acquits and discharges them the said Robert Bannaky and Benjamin Bannaky his son thereon heirs and assign for over one hundred acres of land lying in the said county circumscribed by the bounds hereafter by profit being the moiety of a hundred acres of land.
J. Wells Stokes”

Benjamin grew up on Molly Welsh’s farm, cultivating both the farm and his thoughts. Most of what he was taught was by his grandmother, namely reading and writing. She also taught him religion, though he did not practice a specific faith. Because Oella was remote at the time, his opportunity for formal education was minimal. He did enjoy reading from Molly’s bible and pursuing mathematics. He even taught himself Double Position, a mathematical concept of linear interpolation of an affine linear function. The user inputs an estimated solution, tests it, and then adjusts the following estimate in subsequent iterations. In other terminology, Double Position is also referred to Double False Position and the Rule of Double False. It can be used to solve problems in arithmetic, algebra, and calculus.


Benjamin Banneker’s fascination with math likely precipitated an interest in time, as well. As he grew up, he saw only two timepieces, the first of which was a sundial, the other, a pocket watch. He borrowed this watch and carefully studied it workings, noting every part in great detail. At age 21, he applied his now astute mathematical skill and fabricated his own clock by hand and mostly of wood. There were some parts made from metals, though he was not able to find a spring to suit. Instead, he powered his clock by way of falling weights, a significant difference in design than a pocket watch. Though this was not the first clock built in the American colonies, it was truly a feat of immense imagination, calculation, and skill. All from a man with scarcely any eighth grade education!

Mrs. George Ellicott had visited Banneker, and her daughter remarked on his creation:

“His clock struck the hour, and at their request he gave them an account of its construction. With his inferior tools, with no other model than a borrowed watch, it had cost him long and patient labor to perfect it. It required much study to produce a concert of correct action between the hour, minute, and second machinery, and to cause it to strike the hours. He acknowledged himself amply repaid for all his cares in its construction by the precision with which it marked the passing time.”

Just as remarkably, this clock continued to mark good time until after his death, more than fifty years later.

Banneker spent his spare hours playing both flute and violin, often performing tunes for various visitors to the farm.

Another significant family in Banneker’s life was the Ellicotts, of Bucks County, Pennsylvania. They had recently moved to Maryland in the hope of starting into the grain and cereal business.  They found a tract of land that looked appealing to them, called the Hollow, just West of Oella and Banneker’s farm. It was this area on the Patapsco River that they decided would be the site for the construction of their homes and a mill. It was an agricultural area with the Patapsco to power their mill and navigate to the shipping lanes.

Banneker often visited the site, to exchange banter about the progress of the construction with other onlookers. They had built a boarding house for their labor on the eastern bank, and were beginning construction of the lower mill around 1774.

Not long into the construction, the Banneker farm began to supply the Ellicott projects with poultry, vegetables, fruit, honey and other commodities.

The Ellicotts had completed a boarding house, saw mill, flour mill, and some other buildings and were now embarking on construction of a store to serve both the community and their own boarders and labor. It was this country store that exposed Benjamin to the many locals and passersby, in addition to the Ellicott family themselves.

The Ellicott family projects were exposed to risks. Wild animals, attacks from natives, and natural disasters were all factors against progress. In 1780, a harsh winter, sudden thaw and March rains all contributed to a washout of damaging proportion, forcing reconstruction of many newly completed structures.


George Ellicott, Andrew’s fourth son, was a young surveyor contracted to map and lay out the Baltimore-Frederick turnpike connecting the lower mills to Baltimore. The idea was to improve the road from a cart way to a major thorofare. He was not only able to improve the width and condition of this stretch of road, but trimmed three miles from the route.

In 1788, years after the Ellicott’s arrival, Banneker began to pursue his interest in astronomy. This was possibly precipitated by interactions with young George Ellicott, who had owned an extensive collection of technical books. It could be presumed that he had loaned some of them to Banneker, including James Ferguson’s An Easy Introduction to Astronomy, Advanced Astronomy, and Charles Leadbetter’s A Compleat System of Astronomy, and Tables of Tobias Mayer, among others.

The loan also included a pedestal telescope, drafting instruments and a table sturdy enough to use for the astronomic measurements. It is believed that George Ellicott did not have the time to walk Banneker through any initial instruction, so he tore into the books on his own.

It was at this juncture that Banneker started to pursue celestial body recognition and projections of eclipses. These computations were derived not only by drafting the celestial motions, but by longhand logarithmic calculations as well. Shortly thereafter, he had made his first predicted eclipse, sketched it, and mailed it to George Ellicott, who was out of town on other business. This could only have brought George Ellicott to surprise and delight, as he had not yet offered any firsthand training in these subjects. Banneker made a correction to a small error, and returned another letter:

“I Receiv’d your letter at the hand of Bell but found nothing Strange to me In the Letter Concerning the Number of Eclipses tho according to authors the Edge of the penumber only touches the Suns Limb in that Eclips that I left out of the Number-which happens April 14 day at 37 minutes past 7 O’Clock in the morning and is the first we shall have, but Since you wrote to me I Drew in the Equations   of the Node which will Cause a Small Solar Defet but as I did not intend to publish, I was not so very peticular as I should have been, but was more intent upon the true method of projecting a Solar Eclips- It is an easy matter for us when a Diagram is laid down before him to draw one in resemblance of it, but it is a hard matter for young Tyroes in Astronomy when only the Elements for the projection is laid down before him to draw his Diagram to any degree of Certainty-

Says the Learned Leadbetter the projection that I shall here describe, is that mentioned by Wm. Flamsted- When the Sun is in Cancer, Leo, Virgo, Scorpio, or Saggittary, the Axes of the Globe must lie to the right hand of the Axes of the Ecliptic, but when the Sun is in Capercorn, Aquarious, Pisces, Aries, Taurus or Gemini then to the left-

Says the wise Author Ferguson, when the Sun is in Capercorn, Aquarious, Pisces, Aries, Taurus, and Gemini the Northern half of the Earth Axes lies to the right hand of the Axes of the Ecliptic, and to the left hand whilst the Sun is in the other Six Signs-

Now Mr. Ellicott two Such learned Gentlemen as the above mentioned, one in direct opposition to the other, Stagnates young beginners, but I hope the Stagnation will not be for the duration for this I observe that Leadbetter Count the time on the path of Virtex Count the time 1.2.3 &c. from the left to the right hand according to the order of Numbers, So that that is regular Shall Compensate for irregularity
-Now Sir if I can overcome this difficulty I Doubt not being able to Calculate a
Common Almanack- So no more but remain yr. faithful friend Mr. George Ellicott.
Oct. 13, 1789 – – – B. Banneker”

As it turned out, there was not really an error between Leadbetter and Ferguson’s texts. It was a conceptual difference of illustrating planetary motion. Ferguson used his examples realized from a sun oriented position. In other words, the observer would be at the sun, looking at earth. Leadbetter used his examples from an earth oriented position. The observer would be on earth, looking at the sun. It is presumed that Banneker was wrestling with both texts simultaneously, and could have found some problems with this.

Shortly after this dialogue, George Ellicott suggested that Banneker pursue computations for a full almanac. After having acquired more references, Banneker continued, in earnest, to complete his calculations of eclipses and other astronomical events necessary for a published almanac.

Though almanacs were first distributed in the colonies in 1639, their content expanded from ephemeris to astrology, history, planting schedules, poetry and other minor topics. At this time, these almanacs were used by farmers for handling their crops and harvests. These books also served navigators who would be able to reckon their latitude and longitude by way of the tables to about seventy miles’ resolution.

Martha Tyson, Mrs. George Ellicott’s daughter, details a visit of her family to Banneker’s home in 1790:

“His door stood wide open, and so closely was his mind engaged that they entered without being seen. Immediately upon observing them he arose and with much courtesy invited them to be seated. The large oval table at which Banneker sat was strewn with works on astronomy and with scientific appurtenances. He alluded to his love of the study of astronomy and mathematics as quite unsuited to a man of his class, and regretted his slow advancement in them, owing to the   laborious nature of his agricultural engagements, which obliged him to spend the greater portion of his time in the fields…His mother had died previous to this, and he was the sole occupant of the dwelling.”

Shortly thereafter, Banneker had neatly copied a tabular form of almanac for all of the upcoming months of 1791. It was now time to find a publisher.

At the time, he had a few choices of publishers in Baltimore that might have some interest; Goddard and Angell had no immediate want of his product. A second attempt at another house also failed. For his third try, he sent a copy to John Hayes, who had for years been publishing Major Andrew Ellicott’s almanac. Hayes and Goddard were in a rival business of each printing local almanacs. After some controversy and name calling within the business fronts, Banneker tried several times for a response from Hayes. Hayes had sent a copy to Ellicott in Philadelphia for his vetting. At some juncture, he contacted Major Ellicott himself, hoping to know what caused the delays:

“Maryland Baltimore County near Ellicott’s Lower Mill
May the 6th : 1790

Sr// I have at the request of Several Gentlemen Calculated an Ephemeris for the year 1791 which I presented unto Mr. Hayes printer in Baltimore, and he received it in a very polite manner and told me he would gladly print the Same provided the Calculations Came any ways near the truth, but to Satisfy himself in that he would Send it to Philadelphia to be inspected by you and at the reception of an answer from you he Should know how to proceed and now Sr. I beg you  will not be too Severe upon me but favorable in giving your approbation as the nature of the Case will permit, knowing well the difficulty that attends long Calculations and especially with young beginners in Astronomy, but this I know that the greater and more useful part of my Ephemeris is so near the truth that it needs but little Correction, and as to that part that may be somewhat Deficient, I hope that you will be kind enough to view with any eye of pitty as the calculations was made more for the Sake of gratifying the Curiosity of the public, than for any view of profit, as I suppose it to be the first attempt of the kind that ever was   made in America by a person of my Complection-

I find by my Calculation there will be four eclipses for the ensuing year but I have not yet Settled their appearance, But am waiting for an answer from Your HONOUR to Mr. Hayes in Baltimore-

So no more at present, but am Sr. your very humble and most obedient Serv.
B. Banneker”

Unfortunately, not much is known about any ensuing correspondence in this matter.

The biographer, Silvio Bedini speculates a bit on the above; Banneker’s computations may have been mostly correct yet incomplete. Ellicott may not have wanted to take the time to recompute Banneker’s figures.  All of this brought the delay to impossibility for Hayes to have used Banneker’s almanac for the following year.

Though this was a letdown for Banneker, there were other things brewing in the colonies that may have helped his cause. The anti-slavery movement was on the rise in Philadelphia and other countries. The Continental Congress had already drafted an embargo plan for banning slavery and importation of slaves in 1774. The Revolutionary War had served to disrupt the slave trade and Quakers in both the colonies and England were serving their ethical mores by recruiting and lobbying on behalf of abolition.

Benjamin Franklin was elected the first president of “The Society for the Relief of Free Negroes unlawfully held in Bondage” in 1775, later to be renamed to “The Pennsylvania Society for Promoting the Abolition of Slavery, the Relief of Free Negroes Unlawfully Held in Bondage and for Improving the Condition of the African Race.” This group had been instrumental in their few short years to have included James Pemberton, Benjamin Rush, Elias Ellicott, and Joseph Townsend. Other chapters soon formed in New York, New Jersey, Rhode Island, Delaware, Virginia, and Maryland.

James Pemberton saw Banneker’s letter to Andrew Ellicott and was compelled to introduce it to others in the group. When he showed it to Townsend and others; there was an interest that the group could use for their interests as well. This was Pemberton’s letter to Townsend:

“I have made the inquiry respecting the Negro Man mentioned in my two last- Elias Ellicott informs that the Calculation of the Almanack was nearly brought to perfection but is refer’d to next season- John Hayes says that the author presented it to him in due time for publication, but as he had for years past been in the practice of printing Ellicotts he did not like to Change as his was publickly known by the name of Ellicotts, on which account he objected, not as he had any reason to doubt its exactness- If I can discover anything further respecting him or his performance I shall convey it accordingly-”

A New Venture

For several years, President Washington and others were interested in developing a new federal city.  They generally wanted it to be in the mid-Atlantic, for travel and strategic purposes, but it was not until about 1790 that they had agreed on the Georgetown and Alexandria area. President Washington made the endeavor official by his promulgation of a survey to be done of a ten mile square of this proposed tract.

Major Andrew Ellicott was the choice for surveyor of the new Federal District. He had already represented Virginia in the establishment its boundary with Pennsylvania in 1784, a project he had undertaken with David Rittenhouse, a surveyor and instrument builder, among other skills. In 1786, he and Rittenhouse had also surveyed New York’s borders. They had hoped to use the zenith sector that Charles Mason and Jeremiah Dixon used in the Pennsylvania Maryland border project, but that was not available at the time, so they fabricated their own.

A zenith sector is a telescope that is used as an astronomic instrument. The intent is to set up over an unknown station, observing stars that pass over, or very near, that station’s latitude. Observations of the zenith angle are recorded, as well as time and date of the observation. This makes the zenith sector the useful instrument of the time for accurate determination of latitude and longitude. The accuracy of the overall measurements would mostly be a factor of the accuracy of the time observed, the resolution of the zenith angle observed, and the quality of the published ephemeris. Ellicott and Rittenhouse decided then to build their new instrument to a five and one half foot radius and a five and one half foot focal length, enough to measure to second and third magnitude stars any time of night or day. Smaller instruments would not have provided the accuracy and precision necessary. They did use a secondary zenith sector, for its portability, though it was much less accurate. This backup had a radius of only nineteen inches.

When Ellicott received notice to proceed in February 1791, he now had to choose who would assist him in this ambitious new undertaking. His younger brothers, Joseph and Benjamin, were already dispatched to running the western boundaries of New York State. His next choice was young George Ellicott, his cousin, but at the time he was looking after the day to day operation of the Ellicott’s Lower Mills, in addition to other projects there. It was George who reminded Andrew of Benjamin Banneker’s newly honed skills in mathematics and astronomy.

Although it appears Andrew did want to use Banneker as an assistant, Bedini asserts that Banneker had a penchant for the drink, and presumably made it a stipulation that to work on this project, he would have to be sober.

The next gap to be filled would be to bridge his knowledge of math and astronomy with surveyor’s measurements. It was decided that Banneker, a 60-year-old farmer, would be the main observer of astronomic measurements, note taking, and reduction of computations. All of this happened for him on the most important survey of its time.

One of Ellicott’s first moves would have been to select a site that was suitable for a field observatory. It would have been on a high point, yet had some trees for protection if need be. One of the trees would have been cut down to serve as a stable base for the clock. An accurate clock, again, was a must for successful astronomic measurements. This clock not only needed a good base to rest on, there were temperature constraints as well. Tents and tarps were used to ventilate or protect, depending on drafts and conditions. Thermometers would have been draped in various locations for adjustments to be made and checked. Once the clock was secured, a site to set up the zenith sectors was arranged as well. An observatory tent would have been built with openings for the various telescopes.

Possibly the second most important piece of optics, the transit and equal altitude instrument, another Andrew Ellicott-constructed piece, was built in 1789. It was a theodolite of French influence, and had a striking look. Ellicott had just used this instrument on the West line of New York State, and was very impressed with its performance.

Other, incidental instruments probably included a circumferentor, also known as compass. They probably also used some sort of sextant or quadrant for measuring earth’s moon.

There were likely other telescopes, some for receiving signals, and one with very strong optics for observing occultations of Galilean (Jupiter’s) moons. With good observations of these moons, the times can be compared with an ephemeris. This ephemeris published the appearances of the moons as observed from Greenwich observatory. After some computation, the longitude can be determined from the differences.

Much of Banneker’s efforts were dedicated to looking after the regulator clock that was built by Andrew Ellicott in his shop in Baltimore. It was the best that could be used at the time. Ellicott was having problems recruiting enough bodies for his field crews, but probably acknowledged to himself that the now elderly Banneker should stay at the observation tent to do what he did best.

Ellicott needed bodies for clearing and cutting line, chaining distances, measuring angles in the field, and so on. So far he was severely understaffed.

Ellicott’s initial instructions from Secretary Jefferson were to capture the wharves of Alexandria, Georgetown, and the discharge of the Eastern Branch into the Potomac all enveloped within this ten-mile square. He set out to satisfy this in what was called the four “lines of experiment.” On an existing map, he struck a meridian at Jones’ Point near the Potomac River. From a point on the South edge of town, he struck a line to the northwest, ten miles long. Next line was to the northeast, then to the southeast. The final line was from Jones Point to the northeast, intersecting the third line.

Many difficulties ensued. Ellicott was riddled with the worry of loss of accuracy of his wearing survey chain, of undetected errors from deviation of the compass needle, and the short staffed nature of his survey crew. He knew President Washington and Secretary Jefferson, as well as the three commissioners of the construction of the federal city, were eagerly awaiting progress.

Banneker stayed at the main survey camp, looking after his tasks. On the clear nights, he would be up in the observation tent, looking after the clock, making astronomic observations, recording the notes and reducing them. Often, he would have to stay up all night, making observations, and waiting for Major Ellicott to check on him in the morning. He would check on Banneker’s notes prior to looking after the other people and tasks at the camp.

The day was not exclusively for his rest, though. Banneker had to periodically measure the sun with the transit and equal altitude instrument to compute calibrations for the regulator clock. Often, he would have to take these measurements at mid-afternoon. It was not until then that he would be free of work until night again.

In March of 1791, Secretary Jefferson sent a message to Major Pierre Charles L’Enfant to start drawings for the layout of roads and blocks of the new Federal district, including roads, waterways and topography. It was not made clear to L’Enfant that his commission was subordinate to the three district commissioners, a point that would cause future problems and later lead to his dismissal.

Some historians believe that Andrew Ellicott and Banneker worked as assistants to L’Enfant. Banneker worked for Ellicott, but L’Enfant’s work was engineering, not surveying and astronomy. Each of these two parties answered to the commissioners separately. It could be that Benjamin Ellicott’s occasional work for L’Enfant on the project contributed to the confusion.

On 12 March, 1791, the following notice was published in the Georgetown Weekly Ledger:
“Some time last month arrived in this town Mr. Andrew Ellicot, a gentleman of superior astronomical abilities. He was employed by the President of the United States of America, to lay off a tract of land, ten miles square, on the Potowmack, for the use of Congress;-is now engaged in this business, and hopes soon to accomplish the object of his mission. He is attended by Benjamin Banneker, an Ethiopian, whose abilities, as a surveyor, and an astronomer, clearly prove that Mr. Jefferson’s concluding that race of men were void of mental endowments, was without foundation.

Wednesday evening arrived in this town, Major Longfont, a French gentleman, employed by the President of the United States to survey the lands contiguous to George-Town, where the federal city is to be built. His skill in matters of this nature is justly extolled by all disposed to give merit its proper tribute of praise. He is earnest in the business, and hopes to be able to lay out a plat, of that parcel of land, before the President, upon his arrival in this town.”

Later in March, President Washington traveled to Georgetown to meet with the commissioners and thirteen original proprietors. These 13 were landowners of substantial tracts of land, areas that would be critical to the proposed improvements. He had also met with Majors Ellicott and L’Enfant to inspect their work and to see some of the areas himself.

On the 31st day of March, Major Ellicott received notice to continue the running of the lines. Two weeks later, lines were run from Alexandria, southwest one and a half miles and then southeast to Hunting Creek.

On April 15, 1791, a ceremony was celebrated around the setting of the first stone at Jones’ Point. This was attended by Ellicott, the three commissioners, other city officials, and the public. The ceremony was conducted under principles of Freemasonry, with a stone marked appropriately; with a level representing equality, a plumb representing moral integrity, and a square representing virtue. Once in the ground, it was dedicated with corn as nourishment, wine as refreshment, and oil for harmony.

Though there were difficulties in maintaining accuracy and precision in the work, Ellicott would put away the chain in favor of a more stable distance meter of the time, wood rods with plumbs and micrometers. Bedini describes the actual geometry of the figure as follows; described as a square but more in the nature of a trapezoid. The line from the southern point to the northern point is not a true meridian, but it is 0 degrees 5 minutes 19.7 seconds West of North, converting to a 116 foot error perpendicular to the meridian. The sides were intended to have been ten miles each, but measure:

Southwestern side 53030.6 feet
Northeastern  side 53063.1 feet
Southeastern  side 52870.5 feet
Northwestern side 52863.0 feet

After these four corners were set, the line was cut 20 feet wide on either side of the district’s borders. Milestones were then set along these edges. When it was not possible to set one due to topographic or water obstacles, the marker was “placed on the nearest firm ground.”

That spring, Benjamin Ellicott and Joseph Ellicott completed the New York border project, and came back to the Federal project to help complete it. This allowed Benjamin Banneker the opportunity to return home and pay close attention to his declining health.

Ellicott’s next order of business was two more lines, one being the meridian and the other at right angles to the first. The Capitol Building would be built at this intersection and the President’s House, AKA the White House, would be related to these lines as well.

By September 1791, L’Enfant began to find friction with the board of commissioners. They wanted 10,000 copies of his new map for distribution to the public. Somehow they were never made, and land sales were made without these maps. President Washington defended L’Enfant at this time but was later angered by L’Enfant’s refusal to allow the original map to be displayed at the sale.

L’Enfant’s last straw fell in November 1791 when he was informed that one of the commissioner’s homes was being built out of place, and that it would interfere with the alignment of E Street and New Jersey Avenue. He ordered it to be dismantled, upsetting Carroll, Washington, and Jefferson. L’Enfant argued with them and was removed from duty, by Jefferson in March 1792. This is an important turn of events because many claim Banneker to have helped to finish the road layout by memory. This is not possible, as Banneker had already returned home. In the following weeks, Ellicott replaced L’Enfant and continued the project.

Now that Banneker had returned home, he was able to re focus his efforts on both astronomy and his proposed 1792 almanac. His practice of field astronomy with Major Ellicott had given him confidence to push forward. With his eyes on the scope he made his measurements and with pen in hand he made computations, continuing to draft projections of eclipses, occultations, and other phenomena.

He had invested a substantial amount in a large notebook that would contain rows and columns of both observations and their reductions. By June the manuscript was complete so it was time to find a willing publisher. He looked up William Goddard from Baltimore, as well as an interest from Georgetown. Banneker had impressed Goddard with his mathematical abilities, making him think this publication would be worthwhile for his own print house’s public relations. Both possibilities later seemed to fade in interest, so he had to look elsewhere. He sought publication later in Philadelphia, with the expectation that he could parlay some interest from the Quakers or the Pennsylvania Society for the Abolition of Slavery. George Ellicott and his brother Elias also helped to get interest spread, sending other manuscripts through Baltimore.

Word had made its way from the Ellicott brothers to Joseph Townsend to James Pemberton. The following is a letter from Elias Ellicott to Pemberton:

“Understanding that thee wrote to Joseph Townsend expressing a desire to be informed particularly respecting Benjamin Banaker, I take the Freedom to inform Thee that I am personally Acquainted with him. He is a Black Man about 56 years of Age. His father was a Guinea Negroe. He is a man of strong Natural parts and by his own Study hath made himself well Acquainted with the Mathematicks. About three Years Ago he began to study Astronomy by the Assistance of some Authors which he with much difficulty procured soon became so far a proficient as to Calculate an Almanac, he calculated one for the Year 1791 and Intended to have had it Published but could not. He hath a Copy now ready for the Press for the Year 1792-and is very desirous of having it Published in Philadelphia. Now if Thee thinks it Worthy they notice it might be well to make inquiry of the different Printers to know whether any one of them will undertake to Print it. He is a Poor man & Would be Pleased With having something for the Copy but if the Printer is not Willing to give any thing He would rather let him have it for nothing than not to have it Published. He thinks as it is the first performance of the kind ever done by One of his Complection that it might be a means of Promoting the Cause of Humanity as many are of Opinion that the Blacks are Void of Mental endowments. If thee can find any one that will take the Copy of the Almanac please to inform me by the Post and I will have the Copy Forwarded.

p.s. Said Banaker lives about 10 miles from Baltimore near Ellicotts Lower Mills, it may be depended upon that he never had any assistance from any Person in respect to his Knowledge of Astronomy.”

This triggered an immediate interest dependent on the accuracy of the calculated information, and urged immediate forwarding of the almanac. Elias sent message of the success to George, who the visited Banneker. He had not finished the almanac at the time, as he lay ill in bed. Banneker had struggled through his ills and soon was back to writing. The completed manuscript was quickly delivered to Philadelphia.

That same year, the Maryland Society for the Abolition of Slavery had sponsored Dr. George Buchanan to make a speech during Baltimore’s 4th of July celebration. His speech celebrated the distinguished accomplishments of people of African descent:

“Many instances are recorded of men of eminence among them. Witness Ignacio Sancho, whose letters are admired by all men of taste; Phillis Wheatley,  who distinguished herself as a poetess; the Physician of New Orleans; the Virginia Calculator; Banneker, the Maryland Astronomer, and many others…”

Rittenhouse, the country’s foremost astronomer, had then succeeded Benjamin Franklin as President of the American Philosophical Society following Franklin’s death. After reading Banneker’s manuscript, he remarked to Pemberton, “I think the papers herewith return to you a very extraordinary performance, considering the Colour of the Author” and branded the writing “sufficiently accurate for the purposes of a common Almanac” and “Every Instance of Genius amongst the Negroes is worthy of attention, because their oppressors seem to lay great stress on their supposed inferior mental abilities.”

By now, other publishers had shown interest as well. Joseph Crukshank, a Philadelphia Quaker, and one of the founders of the Pennsylvania Society for the Abolition of Slavery, opened his press, free of charge. There were now three presses duplicating Banneker’s work.

Banneker now began to think not only of the importance of the almanac itself, but of the underlying accomplishment that it helped reflect of his race. In Jefferson’s “Notes on the State of Virginia,” the Secretary of State made conclusions that Banneker’s race of men were void of mental endowments, among other derogatory statements:

“Comparing them by their faculties of memory, reason, and imagination, it appears to me, that in memory they are equal to the whites; in reason much inferior, as I think one could scarcely be found capable of tracing and comprehending the investigations of Euclid; and that in imagination they are dull, tasteless, and anomalous.’

‘They will crayon out an animal, a plant, or a country, so as to prove the existence of a germ in their minds which only wants cultivation.”

This was Banneker’s opportunity to politely retort with his own letter in return:

“…I suppose it is a truth too well attested to you, to need a proof here, that we are a race of Beings who have long labored under the abuse and censure of the world, that we have been looked upon with an eye of contempt, and that we have long been considered rather as brutish than human, and Scarcely capable of mental endowments…

…Sir, I freely and Chearfully acknowledge, that I am of the African race, and, in that colour which is natural to the of the deepest dye; and it is under a Sense of the most profound gratitude to the Supreme Ruler of the universe, that I must confess to you, that I am not under that State of tyrannical thralldom, and inhuman captivity, to which too many of my brethren are doomed; but that I have    abundantly tasted of the fruition of those blessings which proceed from that free and unequalled liberty with which you are favoured and which I hope you will willingly allow you have received from the immediate Hand of that Being from whom proceedeth every good and perfect gift…

…but Sir how pitiable is it to reflect, that although you were so fully convinced of the benevolence of the Father of mankind, and of his equal and impartial distribution of those rights and priveleges which he had conferred upon them, that you should at the Same time counteract his mercies, in detaining by fraud and violence so numerous a part of my brethren under groaning captivity and cruel oppression, that you should at the Same time be found guilty of that most criminal act, which you so professedly detested in others, with respect to yourselves…

…And now, Sir, although my Sympathy and affection for my brethren hath caused my enlargement thus far, I ardently hope that your candour and generosity will plead with you on your behalf, when I make known to you, that it was not originally my design; but that having taken up my pen in order to direct to you a present, a copy of an Almanack which I have calculated for the Succeeding year, I was unexpectedly and unavoidably led thereto.

This calculation, Sir, is the production of my arduous study, in this my advanced Stage of life; for having long unbounded desires to become Acquaintedwith the Secrets of nature, I had to gratify my curiosity herein thro my own assiduous application to Astronomical Study, in which I need not recount to you…

And although I had almost declined to make my calculation for the ensuing year, in consequence of that time which I had allotted therefor being taking up at the Federal Territory by the request of Mr. Andrew Ellicott…”

Copies of these two letters were printed in Philadelphia and saw wide distribution, the same city and about the same time that his 1792 almanac was available.

Mr. Jefferson’s response;

“…No body wishes more than I do to see such proofs as you exhibit, that nature   has given to our black brethren, talents equal to those of other colors of men, and   that the appearance of a want of them is owing merely to the degraded condition of their existence, both in Africa & America. I can add with truth, that nobody wishes more ardently to see a good system commenced…

…I have taken the liberty of sending your Almanack to Monsieur de Condorcet,  Secretary of the Academy of Sciences at Paris, and member of the Philanthropic society, because I considered it as a document to which your whole colour had a right for their justification against the doubts which have been entertained of them…”

Jefferson’s forwarding of the almanac to Condorcet likely reflected a change of thought, as letters from people of their stature were always responded to, and acted upon. Not only was Condorcet the Secretary of the Academy, he was also a member of the French Societe des Amis des Noirs (Society of the Friends of the Blacks), another group that would have been ecstatic to spread Banneker’s fame. Timing was unfortunate as, regrettably, Condorcet was also involved in the suspension of the king and his replacement with a new republic. Soon after, he went into hiding, later being captured and imprisoned. He was found dead in prison in March 1794.

After many machinations of printing, publishing, and foreword letters, the almanac finally hit Goddard/Angell’s press. Two shops in Philadelphia and one in Alexandria printed as well.

Doctor James McHenry wrote the foreword letter to this almanac;

“I consider this Negro as a fresh proof that the powers of the mind are disconnected with the colour of the skin, or, in other words, a striking contradiction to Dr. Hume’s doctrine, that “Negroes are naturally inferior to the whites and unsusceptible of attainments in arts and sciences.”…Let, however, the  issue be what it will, I cannot but wish, on this occasion, to see the Public patronage keep pace with my black friend’s merit.”

Banneker found almost immediate fame, yet attached the credit to the Maryland and Pennsylvania Societies for the Promotion of the Abolition of Slavery. [EJG1]

As he was preparing his computations for the 1793 almanac, his notoriety brought him easy connections with area publishers. One manuscript went to Goddard & Angell in Baltimore, another to Crukshank in Philadelphia. It was Crukshank that parlayed the printing of the almanac with his ideologies of the anti slavery movement.

The Crukshank edition included the correspondence between Banneker and Jefferson, McHenry’s words (above), along with speeches of great notoriety and debates within Britain’s parliament. All these factors together made Crukshank’s 1793 almanac perhaps the greatest all around publication for Banneker.

When the deadline approached for the 1794 manuscript to go to print, Banneker was suffering from another difficult winter and old age. He found himself well behind schedule for completing his computations and drafting the tables for print.

Bedini supposed that Banneker had also been enlisted to composing an almanac for London as he had written letters explaining his delays of both London and Philadelphia almanacs. His notoriety continued to grow, as his almanac was distributed in Britain’s House of Commons by William Pitt, William Wilberforce (skipper of the USS Constellation, a once pirate/slavery interdiction vessel) and others.

After the 1794 Philadelphia almanac was published, Banneker gleaned even greater fame. Copies sold quickly all around. The growing fame even earned him a letter of admiration from Sally Lane in Philadelphia, who forwarded some of her own astronomic calculations. His response included:

“I shall make bold to do my self the pleasure to call upon you, although it seems unlikely it may not be impossible for it to be in my power to be serviceable unto you in some respect or other.”

Banneker added three other printers in Philadelphia for his 1795 almanac. One printer New Jersey also participated, bringing the total to approximately nine. The cover of this almanac included a woodcut image of Banneker’s profile. Crukshank’s version continued to contain speech excerpts concerning slavery and related topics.

The 1796 and 1797 editions were printed, but with limited distribution. His illnesses and old age continued to rail upon him. 1797 proved to be the final year of publication, though computations were found in his notebooks through 1805.

In his late years, Banneker made entries into his manuscript; there were thefts, burglaries and suspicion of intent to his murder by his neighbors and strangers. There was a break in and items stolen. There were gunshots that landed pellets in his small home. Maybe the neighbors thought him to be a wealthy man after his publications. Maybe these miscreants were hunting for stashes of riches within the home. Some entries in his manuscript reflected these thoughts.

On an October morning in1806, Banneker excused himself, and his partner on a walk escorted him back home. Shortly after stretching out for a rest, he passed on. Having reached 74 years, he had left instructions for after his passing. One nephew was to go to the mills and notify the Ellicotts. Another was to return the telescope, table, and books to George Ellicott.

While his body was being lowered into his grave, Banneker’s home suddenly broke into flames, burning the remaining contents. Some of his hand printed manuscripts were lost, along with the clock that kept such remarkable time for upwards of forty years.

The Federal Gazette published his obituary;

“On Sunday, the 9th instant, departed this life at his residence in Baltimore county, in the 73rd [sic] year of his age, Mr. BENJAMIN BANNEKER, a black man, and immediate descendant of an African father. He was well known in his neighborhood for his quiet and peaceable demeanor, and among scientific men as an astronomer and mathematician. In early life he was instructed in the most common rules of arithmetic, and thereafter, with the assistance of different authors, he was enabled to acquire a perfect knowledge of all the higher branches of learning. Mr. B. was the calculator of several almanacs which were published in this, as well as some of the neighboring states, and although of late years none of his almanacs were published, yet he never failed to calculate one every year, and left them among his papers, preferring solitude to mixing with society, and devoted the greatest part of his time in reading and contemplation, and to no books was he more attached than the scriptures. At his decease he bequeathed all his astronomical and philosophical books and paper to a friend.

Mr. Banneker is a prominent instance to prove that a descendant of Africa is susceptible of as great mental improvement and deep knowledge into the mysteries of nature as that of any other nation.”

Eddie Glaw is an LS in Maryland


Bedini, Silvio A., “Andrew Ellicott, Surveyor of the Wilderness.”

Bedini, Silvio A., “Conserving the Boundary Stones,” Washington Post, p. A18 (June 20, 1998).

Bedini, Silvio A., The Life of Benjamin Banneker, Maryland Historical Society, 1999.

Bonnycastle, John, “On Double Position.”

Cowan, John P., “Boundary ‘Error’,” Washington Post, p. 12 (Jan. 3, 1951).

Hooker, Keone, tour guide and historian, Benjamin Banneker Historical Museum, Oella, Maryland.

Ingram, David, PLS, land surveyor, instrument collector, historian.

Jefferson, Thomas, ‘Notes On the State of Virginia.’

Kelly, John, “Arlington Man Watches Over Unsung Monuments to D.C.’s Origins,” Washington Post, p. B3 (May 14, 2009).

Maryland Court of Appeals, “Rusk v. Sowerwine” June 1810.

Tindall, William, “Standard History of the City of Washington from a Study of the Original Sources.”

Tyson, Martha E., “Banneker, the Afric American Astronomer.”





Photographs: Smithsonian Institution, Friends of the Benjamin Banneker Museum

[EJG1]Page 189 chapter 7

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