Benjamin Banneker, a free African-American man, was born in Maryland in 1731. Largely a self-educated farmer, he became a mathematician, astronomer, inventor, writer, and surveyor. In 1761 he built a wooden clock by hand that kept precise time. He learned astronomy and predicted eclipses. He compiled almanacs and became the first black man to be published. He was a member of the commission chosen by George Washington that laid out the plans for the capital city of Washington DC. Banneker wrote a letter to Thomas Jefferson attacking slavery. He is now considered America's first major black man of science.