I was real excited when I saw your message about Baxters around Barbour County, Lewisville and Clio. But then I read on...
I have tons of information on the Caucasian Baxters but not the African-Americans.
However, since the Caucasian Baxters were in the first group of settlers to the area, there probably is a connection. The Thomas Baxter name is very common to the family line. It is even being carried on to my grandson, Thomas Baxter Zabor.
What other names are you researching? I have a Rosa Riley Baxter whose father, Horace Riley is mixed most likely Native American from the area but no telling.