This John Crockett, living in Tenn. was evidently the brother-in-law of James T. Gleaves, and the brother of Malvina Gleaves.
See page 67 – Crockett Family
Malvina & John were children of Samuel Crockett & Elizabeth Campbell Taylor.
This John Crockett married Elizabeth Crockett.
Land Grant is of a different John Crockett.
Dr. Chitwood was a physician in Wytheville, Virginia, who studied Wythe County history in the 1980s and 90s. He was the first person to study these letters and organized them by subject matter. These are his notes for the letters from John Crockett.