My earliest know Hill ancestor is my 2nd great-grandfather James Hill. Information passed down from my grandfather (Luther Jean "Luke" Hill) says that James came from North Carolina to Franklin County, Georgia, taught school for two or three years, then married Zillah Poole and began farming and raising a family.
I have not found independent documentation supporting James Hill being born in North Carolina. The only post 1840 census I find James on (in 1860) indicates he was born in Georgia. In the 1880 census two sons (Washington Floyd Hill and Caleb Pennington Hill) indicate their father was born in Georgia, and a third son (George Lafayette Hill, my great-grandfather) indicates James was born in North Carolina. In 1900 and 1910 George again says his father was born in North Carolina, but on his death certificate it says his father was born in South Carolina.
So, I don't really have any solid evidence that James was born anywhere but Georgia.
I have no information about who his parents or siblings were, either. In combing through the census records for Franklin County, Georgia I found several other Hill families that lived near or next door to the James Hill family. I am trying to find descendants of those Hills, hoping they will do Y-DNA testing which would either rule them out as kin, or support (but not prove) my theory that they are siblings of James.
The 1830 Franklin County Census shows a Thomas Hill born between 1771 and 1780. The next page shows James Hill next door to Anderson Hill, with Caleb Hill another four households away.
The 1840 Franklin County Census shows Anderson Hill with most of the same neighbors, so I surmise he did not move. Next door to Anderson is William R Hill, apparently living where James Hill had lived in 1830. James and Thomas are still in Franklin County, but in a different district, in what is now northeastern Banks County. Caleb is in Alabama in 1840.
James Hill was born about 1801, Anderson Hill about 1806, Caleb Hill about 1810, and William R Hill about 1812. Thomas Hill is the right age to be their father, and in the 1830 census has a son in the right age bracket to be William R Hill.
In 1850 I cannot find Thomas in any census record. William R Hill has living in his household an Elenor Hill age 70, born in Virginia, old enough to be the mother of William R, Caleb, Anderson, and James. In 1880 Anderson Hill indicates both his parents were from Virginia. James died in 1868 and Caleb died in 1850, so we don't know where their parents were born.
Taking all this circumstantial evidence into account, I think it is a reasonable guess that Thomas and Elenor Hill are the parents of James, Anderson, Caleb, and William R Hill.
However, until I find descendants of Anderson, Caleb, and William R and get them to test their Y-DNA, all I have is a mystery.