In SC, we stayed a total of 4 nights at Colleton State Park. Site 3 and 9. Site 9 has a great view of the river. Colleton State Park is located off I-95, exit 68. Very inexpensive, clean and has the friendliest Park Ranger we have ever met.
In West Virginia, on our north bound trip, we stay at Rifrafter's, located off Rt 19 near Fayetteville, WV. It is a privately owned campground. It was OK, small sites, $40/night. We don't plan on staying there again, the sites were just too close together. On the return trip, we stayed two nights at Camp Creek State Park. Camp Creek State Park is situated just 2 ½ miles off Interstate 77 at exit 20. Camp Creek is a beautiful park, definitely our favorite site to date. Lots of hiking trails, clean, and inexpensive.
Enjoy your trip.