Attention - John Harris -
This may not be good information but it sounds a bit promising. There was a James Roberts living in Hall County, GA who some say was born in Anderson County, SC. James R was living in Hall County GA in 1845 and he had a son named William Jefferson Roberts - that's why I said it sounded promising.
James Roberts was born in 1800 and his son was born in 1831, one of about 17 children.
I really know basically nothing about this family as they are not in my Roberts line. I hope you have success in finding your family.