Based on an actual strike against the Empire Zinc Mine in New Mexico, the film deals with the prejudice against the Mexican-American workers, who struck to attain wage parity with Anglo workers in other mines and to be treated with dignity by the bosses. The film is an early treatment of feminism, because the wives of the miners play a pivotal role in the strike, against their husbands wishes. http://libcom.org/forums/northampton-socialist-forum/salt-earth-discussion-28032006