Thanks for the response. That Blackburn is who I meant that I had found in Claiborne Co. But again, I am thinking that is too far east for the two men in question. However maybe the 42nd after its reorganization was operating in an area where this W.A. Blackburn was since the 42nd knew where these two guys had gone. Though that does not explain why those two would have traveled that far east to join a different unit.

And there still is the question of the connection with Wheeler's Cavalry which is in the records of both men. As you say this WA Blackburn was connected with Carter's Cav though perhaps it came under Wheeler at some point.