South Carolina keeps many probate and land records at the state rather than local level. Courthouses did burn, but the biggest problem is that no birth or death records were commonly kept in the time period you are interested in (and that was the same for most of the south and midwest until after the 1900s). People recorded those in family Bibles. The tombstones might be around if they had money to buy them...but likely very weathered by now. In the frontier, marriages were often performed by interant preachers who may or may not have "filed" the returns...and often counties or states away when they got around to it. Unlanded people didn't write wills or have probates. It was pretty simple back then.
Try this website for an overview... http://www.scgenealogy101.com/