From their website: History viewed through the eyes of Hollywood, and even well-meaning historians, is rarely 100% accurate. However, history-based dramas, documentaries and news programs are valuable ways to gain insight into historical subjects.
Movies available on this site are in the public domain in the United States. You can use these for your project.
This is a terrific tool for finding video clips/full-length films.
Do a search on your book or poem, author, time period, culture, or event.
There may be news reels, real-time footage, or other documentaries.