The picture on picturehistory.com appears to be of S.D. McEnery. If you go to Wikipedia and enter "List of Louisiana Governors" the list pops up and beside the names of the Governors are their pictures/paintings. By comparing the pictures of S. D. on Wikipedia and the one on picturehistory.com it looks like they are the same person. It does appear, though, that John and S.D. look an awful lot alike, even for brothers.

By the way, John McEnery did win the election of 1872. Also, I do have a ton of info on the Fourth Louisiana Battalion if you're interested....

Eli Lane