Not sure why you posted this as a response to me, rather than using the info you already have to look for the parentage of your Dr.I'd suggest starting at www.tngenweb.org in your known counties (and their parent counties).
I've looked into the Barclay line enough to feel pretty certain that it's not mine, and I don't have anyting to share on that line.But there is a LOT of Barclay-line info out there.(The descendants of enslaved people are harder to find, of course.)You could also try to get Sands' 'History of Monroe County' from interlibrary loan -- you should be able to get the full title from the Monroe Co Tngenweb site.
Given the other surnames I saw in your posting history, I'd suggest you also look for Eleanor Colson's 'McGehee' website.Good luck.