I saw the movie "Harlan County, USA" this weekend. I recommend it very highly. It is about the 1973 Coal workers strike.
During a previous strike in the same county, Florence Reece - the wife of a striking worker, wrote the song "Which Side Are You On?" and I think it may be the greatest song ever written.
Mrs. Reece sings a few verses of it on the movie, and many people have done versions of it since.
Here are some:
Natalie Merchant (w/ Mrs. Reece in the beginning)
The Washington Squares