Benjamin Banneker (1731-1806) was an African American mathematician, surveyor, astronomer, and publisher of a series of popular almanacs. The details of Banneker’s genealogy and early life are obscure, but it appears he was the child of a free mixed-race mother and manumitted Black father. Banneker was largely self-taught and developed an affinity for astronomy which led him to produce a series of almanacs whose accuracy received praise from the noted Philadelphia astronomer David Rittenhouse. In 1791, he briefly assisted Major Andrew Ellicott in the survey of Washington, D.C. and devoted himself thereafter to producing annual almanacs, the last of which were published in 1797. He died in 1806 following years of alcoholism and, on the day of his funeral, his home and most of his writings were destroyed by fire, leaving only one surviving journal. Following his death, he became a folk hero with stories of his life and accomplishments blending fact and fiction.
Banneker wrote a now-famous letter to Thomas Jefferson on August 19, 1791, sending him a copy of his almanac and challenging the paradox of Jefferson’s slaveholding and authorship of The Declaration of Independence:
… you clearly saw into the injustice of a State of Slavery, and in which you had just apprehensions of the horrors of its condition, it was now Sir, that your abhorrence thereof was so excited, that you publickly held forth this true and invaluable doctrine, which is worthy to be recorded and remember’d in all Succeeding ages. “We hold these truths to be Self evident, that all men are created equal, and that they are endowed by their creator with certain unalienable rights, that among these are life, liberty, and the pursuit of happyness.” … how pitiable is it to reflect, that altho you were so fully convinced of the benevolence of the Father of mankind, and of his equal and impartial distribution of those rights and privileges 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 professedly detested in others, with respect to yourselves.
In his reply to Banneker on August 30, Jefferson wrote,
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 the other colours of men, and that the appearance of a want of them is owing merely to the degraded condition of their existence both in Africa and America. ... I have taken the liberty of sending your almanac to Monsieur de Condorcet ... 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.
The same day, Jefferson wrote to the Marquis de Condorcet:
I am happy to be able to inform you that we have now in the United States a negro, the son of a black man born in Africa, and of a black woman born in the United States, who is a very respectable Mathematician. I procured him to be employed under one of our chief directors in laying out the new federal city on the Patowmac, and in the intervals of his leisure, while on that work, he made an Almanac for the next year, which he sent me in his own handwriting, and which I inclose to you. I have seen very elegant solutions of Geometrical problems by him. Add to this that he is a very worthy and respectable member of society. He is a free man.
Following Banneker's death in 1806, Jefferson’s 1809 letter to Joel Barlow expresses doubts about Banneker’s abilities, reflecting his contradictory views on race and intellectual capacity:
… the whole do not amount in point of evidence, to what we know ourselves of Banneker. we know he had spherical trigonometry enough to make almanacs, but not without the suspicion of aid from Ellicot, who was his neighbor & friend, & never missed an opportunity of puffing him. I have a long letter from Banneker which shews him to have had a mind of very common stature indeed. 
- David Thorson, 6/15/23
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