To be honest, when you were told his grave is probably unmarked is true.
I know where some of mine fell and in all my years have only found one in a marked
grave, and he was prisoner at the Yankee hospital and died there. So he lies in a marked
grave in Savannah, Georgia, with his last name mispelled, but nevertheless, still there.
Good luck in your search because there is always that one in a million chance.