http://www.archive.org/details/salt_of_the_earth
"Salt Of The Earth"
Tells the tale of a real life strike by Mexican-American miners. The story is set in a remote New Mexico town where the workers live in a company town in company owned shacks without basic plumbing. Put at risk by cost cutting bosses, the miners strike for safe working conditions. As the strike progresses the issues at stake grow beyond that, driven by the workers' wives. At first the wives are patronized by the traditional patriarchical culture, however they assert themselves as equals and an integral part of the struggle, calling for improved sanitation and dignified treatment. Ultimately, when the bosses win a court order against the workers preventing them from demonstrating gender roles reverse with the wives taking over the picket line and preventing scab workers from being brought in while the husbands stay at home and take care of house and children.
This film was selected for the National Film Registry in 1992 by the Library of Congress. It became public domain after its copyright was not renewed in 1982.
"Salt of the Earth" was produced, written and directed by victims of the Hollywood blacklist. Unable to make films in Hollywood they looked for worthy social issues to put on screen independently. This film never would have been made in Hollywood at the time, so it is ironic that it was the anti-communist backlash that brought about the conditions for it to be made. In many ways it was a film ahead of its time, mainstream culture did not pick up on its civil rights and feminist themes for at least a decade.
Unfortunately, the source of this copy is not of very good quality, hopefully it can be replaced by a better version.
You can find more information regarding this film on its IMDb page. (this text taken from the Archive page for the film).