Hope you enjoy your history documentaries around WWII, because that's probably the only footage documentary producers will be able to afford. The permission to use the footage which made the movie Eyes on the Prize is now anywhere from $250,000 $500,000 to license. The permission to use the footage has long since expired, and the film makers are unable to cough up that kind of money to relicense it. From the article:
"The owners of the libraries, which are now increasingly under corporate consolidation, see this as a ready source of income," Else says. "It has turned our history into a commodity. They might as well be selling underwear or gasoline."
Little wonder that all the public domain footage from WWII has been picked over for documentaries: not only is it compelling, it's also affordable.