U.S. Government.
Free online movies and documentaries downloads can be done in varied ways. Some sites make use of the Google video button. Just click on the button, then choose go to Google Video, and then click “download”. The second way is to use the Firefox Ad-on. The Third way is to go to Keepvid.com or Video Downloader and follow some simple instructions. Be sure that you download only those contents that are public domain.
Some of the resource sites that house free online movies and documentaries materials in public domain are the following:
Archive.org has a collection of numerous videos. Full-length movies, news broadcasts, and all sorts of videos that are uploaded by users.
Publicdomaintorrents.com. At this site you can have free downloads of a wide choice of movies in public domain using BitTorrent