On 5 Sept. 1791, Robert Carter III (1728-1804), one of the wealthiest men in the United States, filed a deed of manumission at the Northumberland County Courthouse. This document eventually freed more than 500 enslaved African Americans owned by Carter in several Virginia counties. "To retain them in Slavery," Carter wrote, "is contrary to the true principles of Religion & Justice." The deed, structured to withstand resistance by Carter's heirs and neighbors, liberated slaves gradually in small groups. Because children were freed when they reached adulthood, the manumission took decades to complete. Many of the freed people became tenants on Carter's land.