My knowledge is primarily based onthe book "John Chapman of Spotsylvania County, VirginiaThomas Powe of Cheraw, South Carolina and Related Families" by Elsie Chapman Edmonds and published 1971.Of the 421 pages, four are dedicated to the Allen Family and several more pages of county document transcripts in an appendix.
I believe the area where these folks lived is in the area of the current counties of Yadkin, Surry, Wilkes Davies or Rowan.Take a look at a map of TN to see where the Yadkin river forks.Bryan's Mill Creek appears to run through current Rowan County from the north.Unfortunately, I haven't traveled in that area so I don't know the exact location.I do believe the deeds are good enough to find the exact locations of these properties if one puts together a number of documents.
Remember that, back in the beginning of the time of our interest, the county seat was in Rowan, with other counties being created.
Anson created in 1750 from Bladen Rowan created in 1753 from Anson. Surry created in 1770 from Rowan Wilkes created in 1778 from Surry Other counties created later. Davidson created in 1822 from Rowan Davie created in 1836 from Rowan
Thus, the records of families living there from 1750 to 1800 can lie in several courthouses but the actual land may be in a county created years later. E.g., I believe the town of Yadkin is in Davidson County.
The will of Erasmus Withers Allen is recorded in Rowan County (Bk. C p.259)Jesse Bryan is one of the witnesses to this will along with Andrew Hunt and Edward V. Harbin.
Rowan County marriages shows a Thomas Allen married Margere Bryan of John and Sarah Bryan on 5/26/1789.While this is probably Thomas Allen, son of Erasmus Withers Allen, it can't be proven from the simple entry in the marriages.Additional proof is necessary.
A Surry County land grant deed shows a Thomas Allen bought acreage on Bryan's Mill Creek in 1786 adjoing land of Jas Forebush, John Johnson and James Chapman.Several years later this same property passes to Erasmus Withers Allen, probably indicating that Thomas Allen and family had moved on to KY with the Boones and Bryans, his wife's kinfolk.
The will of John Bryan in 1798 (Rowan County), whose wife was Sarah, had married daughters Sarah Allen and Margere Allen.The book doesn't indicate which Allen Sarah married.John's will is witnessed by Thomas Allen, Jacob Grote and Samuel Casey.
It appears to me that documents continued to be filed in Rowan County after some other counties were created.This may indicate their lands were within Rowan county as late as 1800OR it may indicate they simply continued to file in a location with which they were familiar.
Contact me by email if you'd like a genealogy of the Allen line as best I have it.Note that my direct line is Erasmus Withers Allen to daughter Mary Allen who married John Chapman.John and Mary lived in Spotsylvania County, VA so I've haven't done a lot of research in Rowan County nor have I personally verified any of the above records.
After John Chapman's death in 1775 and Mary Allen Chapman's a couple of years later, the minor children were raised by older siblings.My ancestor, Thrashley Chapman, was apparently raised by his half brother, Lt. James Chapman (husband of Elizabeth Allen), until James' death during his Revolutionary War service.Elizabeth re-married and moved to Cheraw, SC along with a number of her siblings (Erasmus' children) and some of the other Chapman children.