Benjamin Banneker, born in 1731, was a man ahead of his time. As a free African American in a time of slavery, Banneker was not welcome in white society, and he spent most of his life on his Maryland farm. There he harnessed his keen and curious intellect to teach himself complex mathematics and astronomy. Banneker secured a place in history with his role in surveying the site for the capital city, Washington D.C., and his published almanacs with precise tide calculations and weather predictions. Also, Banneker himself was one of the first African Americans to speak out against slavery. Banneker's accomplishments were used by abolitionists as proof of the intellectual powers of his race.