The correct answer to this open question is the following.
You have plenty of options to pick the African American individual that you feel most interested in from my following suggestions.
You could choose sociologist W.E.B. Du Bois or former slave Frederick Douglass who became a writer, orator, and social reformer. There is also Booker T. Washington, founder of the Tuskegee College in Alabama. If you want to write about a great African American woman, you can choose the life of Sojourner Truth, and abolitionist an activist that escape from slavery in 1826.