Regarding what prison, my guess would be that he was not taken to a prison but paroled and probably went or was sent, the first time, to Camp Chase, Ohio (Columbus) which, among other things, was a holding place for paroled Union soldiers. It is also possible that he would have been sent there the second time, also, but by then there were numerous small locations that were used in much the same manner. Sorry this probably does not help a lot.