Question: Hercules, also known as "Herculas" or "Uncle Harkless", was a slave who worked at Mount Vernon, the plantation house of who, the first President of the United States?
Sentence (from "Mount Vernon"): In 1739 they embarked on an expansion of the estate that continued under George Washington, who came into possession of the estate in 1754, but did not become its sole owner until 1761.
Relevant evidence: No