Ramey is an Americanization of the French name Remy. There are MANY Remy profiles on Geni -- I entered quite a few!
After the Revolutionary War, the family took advantage of lands opened up in the South and the interior of the continent. The name Remy evolved to Ramey during this period. I would suggest looking for the early Remy families and tracing them downward. Perhaps you will find your Thomas.
Also, the Remy family were Huguenot refugees. Check those projects and resources, as well.
Best of luck to you!