I am pretty sure that the correct name is Robert Acuff. A marriage record from Jefferson County, Tennessee, shows that Robert Acuff and Nettie May Wright were married on 15 April 1894 in Jefferson County. (The clerk wrote "Lettie May Wright," then scratched out the first letter and wrote "N" above it.) They were married by J. A. Ballinger, Justice of the Peace, of Mill Springs Run. The names of "at least two witnesses" were D. A. Ballinger and W. S. Howard. The marriage was recorded the next day (page 185).
If you go to Acuff.org (it's free, but you have to register), you will see that Robert Acuff was the son of Cannon F. Acuff and Nancy Jane DAVIS.