The following letter is occasion-ly found in Ancestry Family Trees (e.g., From: Ancestry) and elsewhere, relating to the Buchanans of Southwest Virginia. I have not located the original source for this. The document is said to be a letter from Grundy Buchanan of Rich Valley to Judge John A. Buchanan of Glade Springs, Washington, County Virginia.  Portions of Rich Valley extend into Smyth County, and it is likely that Grundy lived somewhere along the immediate border between Smyth and Washington. Locus Cove Creek is a likely candidate location. This is significant because a John Buchanan, presumably Grundy's ancestor, settled on "Cove Creek", aka Locust Cove Creek, c. 1774.
Grundy's account is represented as being taken from an "old Bible written by Alexander Buchanan, one of the sons of John Buchanan".
The family relationships for these Buchanan's, including the link to Grundy, is shown in the following diagram. Additional data has been added based primarily on the will of James Buchanan, but includes other data as well. The relationships shown represent a "working understanding" and are subject to change. Color coding provides data about residence of the individuals.
(Obvious typos corrected).
Alexander Buchanan, native of Ireland, had two sons who came to America about the beginning of the 18th century, settled in Chester County, Nottingham Township, Pennsylvania. Their names were James and Archibald.
"Person:James Buchanan (42) came to Augusta County, Virginia, and married Martha Allison of the same county. Their children were:
George and David were the children of James Buchanan’s second wife, Mary Resido,  and I have heard they went to Tennessee.
My great-grandfather Robert Buchanan came to Wythe County as an early settler of this part of the state. My grandfather was a son of Robert and Magaret McCutchan Buchanan; his name was Alexander. His wife was Margaret Walker, both of Wythe, but died in Smyth.
My father was James Augustus Buchanan and my mother Mary Glenn Thomas. Father thought your family and his were the same but could not race the relationship. I send you this paper. You may find something in your old Bible that will throw some light on it.