PJO: "Marion stayed here for November - December 1781 and is in his orderly book."
Fishbrook Plantation owned by Quash. "Follow SC 41 to Huger, turn left onto Lotti Road, turn right onto Fishbrook Lane." This is the basis for the location provided. The owner of the property shown has inforned us that his house is not on the actual site of the Quash house ruins (which he prefers not be disclosed), but is near the border between the Fishbrook and Windsor plantations. This is the basis for lowering the confidence level from 4 to 2 ("somewhere in the vicinity of"). Marion would not have camped at the plantation house, but would simply have been somewhere on Quash's property, very likely near a stream.
Search in MS Streets & Trips for: Fishbrook Lane & Lotti Road
takes you to the intersection. Using "Location sensor", the end of Fishbrook Lane reads 33.14992, -79.79745. Turkey Creek can be seen nearby. Basis of site location.