Editor's PicksList 9 of the Biggest Slave Owners in American History Posted byBy Thomas L. Scott | Published on: December 23, 2014 | Updated on February 23, 2019 CommentsComments (50) Share: Gov. John L. Manning of Ascension, Louisiana: 670 Manning owned at least two plantations holding 670 Blacks against their will. One in South Carolina and another in Louisiana. He was a major supporter of succeeding from the Union. Previous Page Next Page