“Salt of the Earth” is a film inspired by the Empire Zinc strike, a 15-month-long miners' strike in New Mexico against the Empire Zinc Company for its bigoted housing practices and wage theft.
"The real work is being done by people who are not known, that's always been true in every popular movement in history...I don't know how you get that across in a film. Actually, come to think of it, there are some films that have done it. I mean, I don't see a lot of visual stuff, so I'm not the best commentator, but I thought Salt of the Earth really did it. It was a long time ago, but at the time I thought that it was one of the really great movies—and of course it was killed, I think it was almost never shown."