Sung by Mrs. Irene Carlisle at Farmington, Arkansas, 1942. So far as is known, "The Brazos River" has never been collected except for the single instance here given. Mrs. Carlisle learned it herself in 1921 from a hired man who had lived in Texas, but beyond that nothing is known of its origin or of its wider dissemination
I suggest using a sliding capo for this, as the 2 verses are played with capo 3 on and choruses with capo off.
Hence
verse 1 capo 3
Choruses (2) both with capo off.
verse 2 capo 3.
Then for the rest (all choruses) capo off.
Tip slider capo will work easier with a spray of lube on the fret and the back.
Good Luck.!!