“The costume is a flag, but the way we’re getting around that is we have Steve Rogers forced into the USO circuit. After he’s made into this super-soldier, they decide they can’t send him into combat and risk him getting killed. He’s the only one and they can’t make more. So they say, ‘You’re going to be in this USO show’ and they give him a flag suit. He can’t wait to get out of it.
It was never in the comics, because they didn’t really need it. In comics, he puts on the costume and the reader just justifies because of the nature of the medium.”