Old Walton was on the NC/ GA line that borders TN as well.....It went back to Buncombe co. after 1811. Macon co NC, Transylvania co NC, Henderson and Jackson are in the general area too.....(this is from my notes, you might want to double check via Google)
Also helpful, pull up a Ga map showing counties and check the ones on the border....Rabun, Union...and TN counties along the line had 'fuzzy' borders as well.
One of my relatives in that area listed her birthplace: United States, I guess she wasn't sure which state she should call her birthplace...
After 1818, Walton county GA is a place in central GA.