The badge is bugging me! It certainly is American and he is wearing US badges of rank on his collar (2 bars = Lt in the Navy). However there should be a centrepiece, a shield with stars and stripes, to his cap badge. Google any image of a USN offer for comparison, even back in the day. Can't find one exactly like it though so unless someone can find the exact same one I shall put it way in the today's minor mystery tray.
MaxD