Public Domain and Royalty-Free Video Clips
The Prelinger Archives
Pixabay has over 1.3 million images and videos. All contents are released under Creative Commons CC0, which makes them safe to use without asking for permission or giving credit to the artist – even for commercial purposes.
Pond 5 Public Domain Project
Pond 5 is a major supplier of media clips and a good place to sell your own stock footage, images, music and sound effects. But, in addition to the media they have for sale, they have established a section of public domain media that is available for download at no cost. You’ll have to set up a free account to download the clips, but it’s worth the effort. Most of the clips and stills appear to be European and there are a lot of WWII vintage items.