I'm no expert, but here's what I've learned. Is he still alive, if not, is there a grave stone with his military unit on it? If he registered a copy of his Discharge Papers with a County Records where he lived, that's a good place to start. And then you could write to the (Army) National Personnel Records Centers with a form 180, address and form available on line, to request the records. There was a fire at their St Louis facility in 1973 and many records were lost. So, be prepared for that, but some information should be available.Good luck. My dad was in the 82nd Airborne. They had a rough time and many were lucky to come out alive.