Paul,
Most of South Carolina's reenactment units are under an umbrella organization called the "Palmetto Battalion."
Go to the Battalion website:
http://www.palmettobattalion.org/
There you will find member organizations and their locations. Make your choice. Pick an infantry, artillery or cavalry company close to you and give them a call. You'll also find schedules and much information about the structure of the Battalion.
Hope it works out for you. It's a great and memorable lifestyle.