I can only speak for Europe but the wedding ring the guy behind the coulourbearer is wearing would have been atypical 4 the time (much to broad and I think wrong material)
"I dreamed about them cotton fields of home
I dreamed about my mother, dear old pappy, sister and brother
And I dreamed about the girl who's been waitin' for so long
I want to go home
I want to go home
Oh, how I want to go home"
I had to look up Chuck Roberson! Only to discover I've seen him in a couple dozen movies with John Wayne. In most of them he is uncredited. And there was a Good Chuck.
Good kit all round in the photo, all the fellows the right age, but imho far too clean to be campaign infantry. The Color Bearer has a nice patina of dirt over his kit, the rest, I'm afraid, look like 'bandbox' soldiers.