He used the middle initial "R", but had NO Middle name.
Colonel - July 5th 1864. Mustered Out Aug 10th 1864.
Bvt. Brig.General USV- Nov 21st 1865 (War Service )
Edit - Welcome to the trivia game, Virginian Sharpshooter.
This was a bit of a confusing question, since it was a three-part question and there were several possible correct answers to the third part (which asked about Dawes' rank).
Actually, "colonel" was not one of the possible correct answers - that was the rank which he was offered, but refused.
However, since this is your first time playing and "brevet brigadier general" was one of the correct answers (and since you correctly specified his name in a subsequent post), you will get credit for a correct answer. Be cautioned, however, that it is generally not a good idea to give two or more different answers to a single part of a question, because in the future, if you do that, you will be marked wrong if any of the answers is incorrect.
Hope you'll come back and play again.
Hoosier