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Benjamin Banneker

  • Academic
  • Surveyor

Biography written by Caroline Clough

Benjamin Banneker was an African American astronomer, mathematician, author, and abolitionist who made significant contributions to cartography, especially through his assistance in surveying the territory for the capital of the newly established United States.1 He is best known for making advancements in several technical fields despite societal and legal limitations placed on him based on his race, as well as for appealing for racial equality at a time when speaking out on the subject was a punishable offense by law.

Banneker was born free on November 9, 1731, and grew up on his family’s tobacco farm in the Patapsco Valley in what is now Oella, Maryland.2 From a young age, Banneker showed an interest in mathematics and mechanics. He attended a Quaker school, which was known for accepting a racially diverse body of students. He gained notoriety among townspeople when he hand-carved a wooden clock that kept perfect time in his early twenties.3 Both his formal education and innate talents helped him launch a career in the sciences and inspired his drive to promote racial equality.4

In 1771, Banneker met the Ellicotts, a Quaker family who purchased a tract of land near Banneker’s family farm on which they intended to construct gristmills.5 He forged a close connection with George Ellicott, a mathematician and amateur surveyor.6 Ellicott introduced Banneker to astronomy, a subject that proved to be a lifelong passion and led Banneker to forecast his first eclipse in 1789.7

In 1791, President George Washington established a commission to survey the new capital city along the Potomac River.8 The commission consisted of three members, including Andrew Ellicott, George Ellicott’s cousin.9 Andrew hired Banneker to assist with the survey, and Banneker set out with him in February 1791. Nearing sixty, Banneker’s health did not acclimatize him well to winter weather, so his contributions were mostly done in the observation tent where he maintained the regulator clock to determine latitude lines.10 In April 1791, after three months of work, Banneker returned home due to his failing health.11

Because few recorded the specifics of Banneker’s involvement, it is difficult to establish the extent of his influence on the project.12 It is known, however, that Banneker likely made the astronomical calculations necessary to establish the south cornerstone of the city.13 In total, the land Andrew Ellicott and his team surveyed and mapped encompassed one hundred square miles and set boundary mile markers along the borders of what is now Washington, DC.14 Banneker’s contributions appeared in Ellicott’s 1792 The Plan of the City of Washington in the Territory of Columbia.

a black and white engraved image of a city plan--Washington, DC--on the east bank of a river
Andrew Ellicott's plan of Washington, DC, which Banneker assisted in surveying.

After returning from his work with Ellicott, Banneker did not let his health impede his pursuit of astronomy, writing, and the fight for racial equality. Between 1791 and 1797, he published an annual almanac to help farmers to predict weather patterns and included essays, farming recommendations, and testimonials from the independent editors who chose to review his work.15 Many testimonials couched praise for Banneker’s abilities in racial—and racist—terms, commenting on how exceptional he was in comparison to white notions of the capabilities of African Americans. Banneker was frequently, in his own words, “annoyed to find that the subject of [his] race [was] so much stressed.”16

Banneker’s frustration with racist policies and beliefs adversely affecting African Americans in eighteenth-century America is expressed in an August 19, 1791, letter to Thomas Jefferson, a prolific enslaver who was then Secretary of State. In the letter, Banneker presented a strong case for equal rights and abolishing slavery, and he included a copy of his almanac. He appealed to religion to make his argument: “One universal Father hath given being to us all… however diversified in Situation or colour, we are all of the Same Family, and Stand in the Same relation to him.” Banneker further noted that Jefferson himself had fought against “the injustice of a State of Slavery” during the American Revolution.17 In his reply, Jefferson thanked Banneker for the almanac and commented that, “Nobody 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.”18 Banneker showed incredible bravery in challenging a figure as elite and powerful as Jefferson.

Benjamin Banneker died on October 9, 1806, at his farm in Oella. He never married or had children, and most of his belongings burned in a fire that destroyed his home just days after his death, leaving the details of his life largely open to interpretation through public records and his letters.19 He is remembered as a trailblazer of abolitionism and a pioneer in astronomical sciences. His name and likeness have been used as a symbol of these values for a multitude of recreational and cultural facilities, as well as schools and streets throughout the United States.

Banner image: detail from Maxime Seelbinder, Benjamin Banneker: Surveyor-Inventor-Astronomer, c.1943.


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

Cerami, Charles. Benjamin Banneker: Surveyor, Astronomer, Publisher, Patriot. New York: John Wiley and Sons, 2002.

Keene, Louis. “Benjamin Banneker.” The White House Historical Association. Accessed October 13, 2023.

National Capital Planning Commission. Boundary Markers of the Nation’s Capital: A Proposal for their Preservation and Protection. Washington, DC: U.S. Government Printing Office, 1976.

Norris, J. Saurin. A Sketch of the Life of Benjamin Banneker From Notes Taken in 1836. Baltimore: J.D. Toy, 1854.

Peters, Richard, ed. The Public Statutes at Large of the United States of America. Vol. 1. Boston: Little and Brown, 1850.


  1. Louis Keene, “Benjamin Banneker,” The White House Historical Association,

  2. Keene, “Benjamin Banneker.”

  3. J. Saurin Norris, A Sketch of the Life of Benjamin Banneker From Notes Taken in 1836 (Baltimore: J.D. Toy, 1854), 5.

  4. Norris, A Sketch of the Life of Benjamin Banneker, 5.

  5. Silvio Bedini, The Life of Benjamin Banneker (Baltimore: Maryland Historical Society, 1999), 55.

  6. Bedini, The Life of Benjamin Banneker, 73-74.

  7. Norris, A Sketch of the Life of Benjamin Banneker, 8.

  8. Richard Peters, ed., The Public Statutes at Large of the United States of America (Boston: Little and Brown, 1850), 1: 130.

  9. George Washington to Henry Knox, September 4, 1789, Founders Online, National Archives,

  10. Keene, “Benjamin Banneker.”

  11. National Capital Planning Commission, Boundary Markers of the Nation’s Capital: A Proposal for their Preservation and Protection (Washington, DC: U.S. Government Printing Office, 1976), 1791.

  12. Bedini, The Life of Benjamin Banneker, 109.

  13. National Capital Planning Commission, Boundary Markers of the Nation’s Capital, 1791.

  14. National Capital Planning Commission, Boundary Markers of the Nation’s Capital, 1793.

  15. Keene, “Benjamin Banneker.”

  16. Charles Cerami, Benjamin Banneker: Surveyor, Astronomer, Publisher, Patriot (New York: John Wiley and Sons, 2002), 150.

  17. Benjamin Banneker to Thomas Jefferson, August 19, 1791, Founders Online, National Archives,

  18. Thomas Jefferson to Benjamin Banneker, August 30, 1791, Founders Online, National Archives,

  19. Keene, “Benjamin Banneker.”