Before marrying George Washington, Martha was already a rich, Virginia widow with acreage and slaves. George had slaves, too, and once elected president, the family moved to Philadelphia which was the temporary capitol of the new United States. He brought slaves with them. But a state law allowed servants who lived in Pennsylvania for 6 months to petition themselves free. Our first president moved his slaves back to Virginia before the 6 months were up and transported other slaves to Philadelphia to reset the count and prevent slaves from legally claiming freedom.