The United States copyright laws are designed to prevent people from copying and distributing other people's work without permission. This includes both paper copies (i.e., photocopies, typewritten copies, etc.) and electronic copies (scanned or uploaded).
In an academic setting there is a fair use exception to the permission requirement, but it is only available if you meet the guidelines. If you do not meet the guidelines, permission must be sought.
Library of Congress American Memory Collection
Several hundred early motion pictures are viewable in the Library's American Memory collections.
The Internet Archive - Movies
Welcome to the Archive's Moving Images library of free movies, films, and videos. This library contains over a million digital movies uploaded by Archive users which range from classic full-length films, to daily alternative news broadcasts, to cartoons and concerts. Many of these videos are available for free download. Check our FAQ for more information.
Flickr Creative Commons
Many Flickr users have chosen to offer their work under a Creative Commons license, and you can browse or search through content under each type of license. The different licenses include:
Briefly...
Attribution:
You let others copy, distribute, display, and perform your copyrighted work - and derivative works based upon it - but only if they give you credit.
Noncommercial:
You let others copy, distribute, display, and perform your work - and derivative works based upon it - but for noncommercial purposes only.
No Derivative Works :
You let others copy, distribute, display, and perform only verbatim copies of your work, not derivative works based upon it.
Share Alike:
You allow others to distribute derivative works only under a license identical to the license that governs your work.
BestPhotos.US
Images from a variety of Federal agencies (Fish and Wildlife, National Parks Service) organized by category.
Library of Congress Digital Collections
Prints, photographs, historic newspapers, and more.
dig.ccmixter
dig.ccmixter is devoted to helping you find great music, all of which is liberally licensed under a Creative Commons license so you already have permission to use this music in your video, podcast, school project, personal music player, or where ever.
Freesound
Freesound aims to create a huge collaborative database of audio snippets, samples, recordings, bleeps, ... released under Creative Commons licenses that allow their reuse.
Jamendo
Jamendo is a platform for the online distribution of musical works under Creative Commons licences.
Library of Congress Online Audio Collection
The Library provides access to a portion of its audio collections through the Recorded Sound Reference Center's web page, the American Memory site, The Performing Arts Encyclopedia and the American Folklife Center pages.