Prominent among black abolitionists were Frederick Douglass, Harriet Tubman (ca. 1820-1913), Sojourner Truth (ca. 1797-1883), the Reverend Henry Highland Garnet (1815, 1882), and Frances Harper (1825-1911).
The self-trained black scientist Benjamin Banneker (1731-1806) was the compiler of The Pennsylvania, Delaware, Maryland, and Virginia Almanac and Ephemeris, published annually from 1791 to 1802. He sent the manuscript of the first almanac to future U.S. president Thomas Jefferson, who was then secretary of state.
With the manuscript, Banneker included a letter in which he protested slavery and disputed Jefferson’s claim that blacks were intellectually inferior to whites. Abolitionists used the almanacs as evidence of the intellectual capabilities of blacks.
In 1789, President George Washington had appointed Banneker to the commission planning the construction of Washington, D.C. Banneker helped survey the future site of the national capital between 1790 and 1793.