Inventor & Author Benjamin Banneker
Benjamin Banneker, a free Black man born in the 1700s, is best-known for building America’s first clock which was built from wood and worked for decades before being destroyed in a fire. While he had a bit of formal education, most of what he knew he taught himself—and he knew a lot. Banneker created an irrigation system for his family’s farm that helped it yield a harvest even during droughts, he compiled and published almanacs after accurately predicting a solar eclipse, and he was part of the surveying team that designed the layout of Washington, D.C. Additionally, Banneker wrote a letter to Thomas Jefferson, encouraging him to abolish slavery.
Further reading: https://www.biography.com/scientist/benjamin-banneker