GW: Life & Times
Slide 11 — A Last Word on Slavery: Washington's Will«back
Washington's attitude toward slavery has been a topic of great interest in recent years.At the time of his retirement, there were 317 slaves at Mount Vernon. Of these, 124 belonged to Washington, 153 were "dower" slaves who belonged to the estate of Martha's first husband and would go to Custis family heirs, and 40 others were leased from a neighbor.
Although he had both inherited and bought slaves as a young man, there is evidence in his letters that Washington was uncomfortable with the arrangement as he grew older. While still President in 1794, he wrote his secretary about a desire "to liberate a certain species of property I possess, very repugnantly to my own feelings, but which imperious necessity compels." (Link here to letter at the Library of Congress: George Washington Papers).
GW died on the evening of December 14, 1799 of acute epiglottis--a condition that caused his throat to close up so that he could no longer breathe. Washington's very detailed 29-page will offers insight into his final thoughts on the subject of slavery.