Banneker, Benjamin

November 9, 1731
October 9, 1806

Benjamin Banneker was an amateur astronomer and the first African-American man of science. He was born free in Baltimore County, Maryland, the son of a freed slave from Guinea named Robert and Mary Banneky, the daughter of a formerly indentured English servant named Molly Welsh and her husband Bannka, a freed slave who claimed to be the son of a Gold Coast tribal chieftain.

Raised with three sisters in a log house built by his father on his 100-acre farm near the banks of the Patapsco River, Banneker received no formal schooling except for several weeks' attendance at a nearby Quaker one-room schoolhouse. Taught to read and write from a Bible by his white grandmother, he became a voracious reader, borrowing books when he could. He was skillful in mathematics and enjoyed creating mathematical puzzles and solving others presented to him. At about the age of twenty-two he successfully constructed a wooden striking clock without ever having seen one. Banneker approached the project as a mathematical problem, working out relationships between toothed wheels and gears and painstakingly carving each from seasoned wood with a pocketknife. The clock continued telling and striking the hours until his death. Banneker cultivated tobacco, first with his parents and then alone until about the age of fifty-nine, when rheumatism forced his retirement. He was virtually self-sufficient, growing vegetables and cultivating orchards and bees. Banneker espoused no particular religion or creed, but he was a very religious man, attending the services and meetings of various denominations held in the region, although he preferred those of the Society of Friends.

It was during his retirement that Banneker became interested in astronomy, after witnessing a neighbor observing the stars with a telescope. With borrowed instruments and texts and without any assistance from others, Banneker taught himself sufficient mathematics and astronomy to make observations and to be able to calculate an ephemeris for an almanac. His efforts to sell his calculations for 1791 to a printer were not successful, but he continued his celestial studies nonetheless.

Banneker's opportunity to apply what he had learned came in February 1791, when President George Washington commissioned the survey of an area 10 miles square in Virginia and Maryland in which to establish the national capital. Unable on such short notice to find an assistant capable of using the sophisticated instruments required, the surveyor Andrew Ellicott selected Banneker to assist him until others became available. During the first three months of the survey, Banneker occupied the field observatory tent, maintaining and correcting the regulator clock each day, and each night making observations of the transit of stars with the zenith sector, recording his nightly observations for Ellicott's use on the next day's surveying. During his leisure time, he completed calculations for an ephemeris for 1792. Banneker was employed on the survey site from early February until late April 1791 and then returned to his home in Baltimore County. Records of the survey state that he was paid $60 for his participation and the costs of his travel.

Shortly after his return home, Banneker sent a handwritten copy of his ephemeris for 1792 to Secretary of State Thomas Jefferson, because, he wrote, Jefferson was considered "measurably friendly and well disposed towards us," the African-American race, "who have long laboured under the abuse and censure of the world … have long been looked upon with an eye of contempt, and … have long been considered rather as brutish than human, and scarcely capable of mental endowments" (Jefferson-Coolidge Papers, I.38–43, Massachusetts Historical Society). Banneker submitted his calculations as evidence to the contrary and urged that Jefferson work toward bringing an end to slavery. Jefferson responded promptly: "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 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 & America…. no body wishes more ardently to see a good system commenced for raising the condition of both their body & mind to what it ought to be, as fast as the imbecillity of their present existence, and other circumstances which cannot be neglected, will admit" (Thomas Jefferson Papers, f.11481, Library of Congress).

Excerpt of Benjamin Banneker's Letter to Thomas

…. Sir,…I hope you cannot but acknowledge that it is the indispensable duty of those, who maintain for themselves the rights of human nature, and who possess the obligations of Christianity, to extend their power and influence to the relief of every part of the human race, from whatever burden or oppression they may unjustly labor under…. Sir, I have long been convinced, that if your love for yourselves, and for those inestimable laws, which preserved to you the rights of human nature, was founded on sincerity, you could not but be solicitous, that every individual, of whatever rank or distinction, might with you equally enjoy the blessings thereof; neither could you rest satisfied short of the most active effusion of your exertions, in order to their promotion from any state of degradation, to which the unjustifiable cruelty and barbarism of men may have reduced them.

Sir, suffer me to recall to your mind that time, in which the arms and tyranny of the British crown were exerted, with every powerful effort, in order to reduce you to a state of servitude: … reflect on that time, in which every human aid appeared unavailable, and in which even hope and fortitude wore the aspect of inability to the conflict, and you cannot but be led to a serious and grateful sense of your miraculous and providential preservation….

This, Sir, was a time when 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 that your abhorrence thereof was so excited, that you publicly held forth this true and invaluable doctrine, which is worthy to be recorded and remembered in all succeeding ages: "We hold these truths to be self-evident, that all men are created equal; that they are endowed by their Creator with certain unalienable rights, and that among these are, life, liberty, and the pursuit of happiness." …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 these rights and privileges, which he hath 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.

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

And now, Sir, I shall conclude, and subscribe myself, with the most profound respect,

Your most obedient humble servant,

benjamin banneker

Jefferson sent Banneker's calculations to the Marquis de Condorcet, secretary of the French Academy of Sciences, with an enthusiastic cover letter. There was no reply from Condorcet because at the time of the letter's arrival he was in hiding for having opposed the monarchy and having supported a republican form of government. The two letters, that from Banneker to Jefferson and the statesman's reply, were published in a widely distributed pamphlet and in at least one periodical during the following year.

Banneker's ephemeris for 1792 was published by the Baltimore printer Goddard & Angell with the title Benjamin Banneker's Pennsylvania, Delaware, Maryland, and Virginia Almanack and Ephemeris for the Year of Our Lord 1792. It was also sold by printers in Philadelphia and Alexandria, Virginia. He continued to calculate ephemerides that were published in almanacs bearing his name for the next five years. Promoted by the abolitionist societies of Pennsylvania and Maryland, Banneker's almanacs were published by several printers and sold widely in the United States and England. Twenty-eight separate editions of his almanacs are known. A recent computerized analysis of Banneker's published ephemerides and those calculated by several contemporaries for the same years, including those by William Waring and Ellicott, has revealed that Banneker's calculations consistently reflect a high degree of comparative accuracy. Although he continued calculating ephemerides through the year 1802, they remained unpublished.

Banneker died in his sleep following a morning walk on October 9, 1806, one month short of his seventy-fifth birthday. He was buried several days later in the family graveyard within sight of his house. As his body was being lowered into the grave, his house burst into flames, and all of its contents were destroyed. The cause of the fire remains unknown. Fortunately, the books and table he had borrowed, his commonplace book, and the astronomical journal in which he had copied all of his ephemerides had been given to his neighbor immediately following his death and thus were preserved.

See also Science

Bibliography

Bedini, Silvio A. "Benjamin Banneker and the Survey of the District of Columbia." Records of the Columbia Historical Society 69–70 (1971): 120–127.

Bedini, Silvio A. The Life of Benjamin Banneker: The First African-American Man of Science. 2d ed., rev. and exp. Baltimore: Maryland Historical Society, 1999.

Latrobe, John H. B. "Memoir of Benjamin Banneker." Maryland Colonization Journal, n.s., 2, no. 23 (1845): 353–364.

Litwin, Laura Baskes. Benjamin Banneker: Astronomer and Mathematician. Berkeley Heights, N.J.: Enslow, 1999.

Tyson, Martha E. "Banneker, the Afric-American Astronomer." From the Posthumous Papers of Martha E. Tyson. Edited by her daughter. Philadelphia: Friends' Book Association, 1884.

silvio a. bedini (1996)
Updated bibliography