After the death of his wife, Frances Ann Tasker Carter, in 1787, Carter embraced the Swedenborgian faith and freed almost 500 slaves from his Nomini Hall plantation and large home in Westmoreland County. By a “Deed of Gift” filed with the county courts in 1791, he began the process of manumitting slaves in his lifetime and continued after his death. His manumission is the largest known release of slaves in North American history prior to the American Civil War and the largest number ever manumitted by an individual in the US.
From Baptist and Swedenborgian influences, Carter concluded that human slavery was immoral. He instituted a program of gradual manumission of all slaves attached to his estate. He designed the program to be gradual to reduce the resistance of white neighbors. Frequently, Carter rented land to recently freed slaves, sometimes evicting previous white tenants in the process. Toward the end of his life, Carter moved from Virginia to Baltimore, Maryland. In part he wanted some distance from family and neighbors who looked askance at his Swedenborgian faith and program of manumission.