Well, I'm in INdiana so all I can tellyou is what I've found online.The Lawson-McGhee library is a big library in (or near) Knoxville TN. (Monroe Co)
The Barclay McGhee family was very wealthy, and had lots of land in that area.Tyson-McGhee airport is also named after them.
No information seems to be available (at least online) on anyone earlier than Barclay's father John, who was an early Federal Indian agent in that area -- the area had long been a major link in the Indian trade routes.
There does not *seem* to be a connection between the Barclay line and several other McGee/McGhee lines that stem from E TN -- if you find such a link, please post it for the world to see!