August 1st, 1791, Robert “Councillor” Carter III, one of the one of the wealthiest slave-owners in all of American history; set in motion The Deed of Gift- the single largest act of liberation in American history prior to the Emancipation Proclamation. On September 5, 1791 he filed the “deed” with the Northumberland County courthouse, manumitting 452 slaves. It is said to be the largest emancipation by an individual person in the United States before 1860. (
http://www.encyclopediavirginia.org/Carter_Robert_1728-1804)