This page collates, with permission (!), content from the Public Domain guide created by Jenny Strickland, Fine Arts Librarian. Some of the sheet music was from Kris Shanton, Music Librarian.
A couple of articles sent by Prof. Crane brought new sites to my attention; I incorporated them, below.
If you need to license news footage, here are a few sources:
Footage.net is a site where you can discover and license footage. Vanderbilt Television News Archive is a site to discover news -- but they do not license content.
Suggestions for additional sources are appreciated. Email me: Cathy Michael
After running a search in YouTube, click on the Filter button. Under the Features column, select Creative Commons.
Example: Documentary