Tennessee was once part of the Carolina Territories. North Carolina ceded its western land in 1790 and Tennessee became, "South of the Ohio River". Tennessee remained as such until 1796 wwhen Tennessee obtained its statehood.
You can visit the Tennessee Archives on the internet and get better information on Tennessee and its formation.
Tennessee, early in its development, was also called "The State of Franklin. That name, of course did not last long and never developed very well.
My research deals, for the most part, the Tennessee Counties of Hancock, Hawkins, Grainger, Hamblen, Jefferson, and in Virginia, Scott and Lee County.
I have lots of problems with Hancock County Tennessee due to its regular destruction of official papers stored in the courthouse. The destruction (some records say 3) was by fire. Most records were destroyed. as late as the 1930's.
I have not been able to determine if my early family history was in Surry County Virginia or Surry County N.C.
I can understand your problem and wish you the best of luck.