If he was in the Army, you can contact the US Military, and ask them to forward a letter for you. If he doesn't reply, assume that he doesn't want to be found. Another thing, it may take a long time for the letter to reach him. If I could remember where I sent our letter (to hubby's dad), I'd tell you. Post a query on a Military mailing list, and I'll bet that someone there could tell you how to do it. You'll need to give them as much information on him as you can, so they can identify the correct serviceman.