p.91., note 138, p.498, quotes Davies, Documents of the American Revolution, Vol.XX, p.72; Draper Sumter Papers, 10VV69 and says that Belleville was 2 miles away from Manigault's Ferry. There must have been two Manigault's ferries, since Cornwallis referred to one about 5 miles above Nelson's Ferry.
p.64. James Postell's raid of Manigault Ferry is described but sounds more like the locale further south.
Terry W. Lipscomb, Names In South Carolina, "South Carolina Revolutionary Battles, Part Five", University of South Carolina, Winter 1977, p.13:
There were two old ferries on the Santee river
bearing the name of Manigault's. One was located in
Orangeburg County northwest of Vance, the one most
prominent in the Revolution was present Calhoun County
not far below the junction of the Congaree and Wateree.
RevWar75listing. 31 Jan 1781. This likely refers to the locale further south.
Barefoot, Touring ..., p.284, suggests a site immediately east of Fort Motte and Thompson's Plantation. 33.731248, -80.628415.