I'll second what Bill D says. Like him, I'm fortunate enough to live in an area where there are many traditional singers and sing-arounds. I may live in one of the few neighborhoods in the U.S. where ballads are still sung socially. (If you're ever in the DC area, let us know; it'll be an excuse to get together and schedule a special sing-around.)

Looking in your area, however, figuring you need something local, I googled for "traditional music" rather than "folk music", and came up with:

Charlotte Folk Society: http://www.folksociety.org/
PineCone Piedmont Council of Traditional Music (Triangle NC): http://www.pinecone.org/
Columbia (SC) Traditional Music and Dance Society: http://www.contracola.org/
Atlanta (GA) Area Friends of Folk Music: http://www.aaffm.org/

The Hornpipe, Folk Music in the Southern Regions: http://www.hornpipe.com/hp/index.htm (a webpage that begins talking about traditional music in Spartanburg, SC)

also investigate:
Swannanoa Gathering, Swannaoa, NC
Blue Ridge Old Time Music Week, Mars Hill, NC
John Campbell Folk School, Brasstown, NC

And in Marshall, NC: Traditional Music at the Depot, Every Friday, 7pm, Main Street in Marshall, NC. Free, donations accepted. (http://www.madisoncounty-nc.com/info/events.html)

Once you find the first few folks in your area, you'll probably wind up networking into the rest of them, but finding the first ones can be like looking for a guitar-pick in a haystack. And once you meet some locals, you can form your own core. The editor of the Hornpipe sounds like somebody you need to meet.

--Charlie Baum