u2jedi: It was funded by the citizens so yes it should all be public domain. In fact a copy of the film reels should have been archived in the Library of Congress.
UnashamedWeeb: You'll need to determine the license of every artistic work before you can actually call it public domain. If the work is owned by federal US government agencies, then it's public domain. You're both assuming your national government hired filmographers/journalists to produce the work or outright bought the work to declare it public domain, etc.
If Konami had to license it, that strongly implies
that another private company owns/owned the work and renewed its copyright before the 28th year. Therefore, those clips are not in public domain.
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Sargon is right with devpubs outright buying the licensed work that their contracted composers/other artists make to avoid future copyright hassles. Unfortunately, this has to be planned thoroughly during the game's production to avoid such scenarios if they didn't want to spend any effort changing the licensed work in the future when it expires.
I am not BROADLY calling Public Domain as it is a well known fact that the US Military PAID Hollywood studios to either film the war or produce Pro-WWII footage. Frank Capra in fact was paid too.