August 19
On August 19, 1791, Benjamin Banneker wrote a letter to then Secretary of State Thomas Jefferson, regarding his slavery stance.
Benjamin Banneker quoted the Declaration of Independence to make his argument against slavery.
Sources
A&E Television Networks. (n.d.-a). Benjamin Banneker writes to Thomas Jefferson, urging Justice for African Americans | August 19, 1791. History.com. https://www.history.com/this-day-in-history/benjamin-banneker-writes-letter-to-thomas-jefferson-slavery