Famous forbidden film in the U.S. during the 1950s, it is one of the first to show the struggle for the emancipation of women, taking almost a feminist political and social perspective. Persecuted and blocked by the Committee of the House of Representatives on Anti-American Activities (HUAC), they succeed in that anticommunist hysteria that the shooting culminates in a tragic way when the sets are set on fire and Rosaura Revueltas, starring actress, is deported to Mexico by the American Immigration Service.
The plot describes a long and difficult strike, based on the 1951 fight against the Empire Zinc Company in Grant County, New Mexico. In the film the company is identified as the "Delaware Zinc," and the population is "Zinctown", New Mexico. The tape shows how the miners, the company and the police respond during the strike, placing more prominently the disposition of women when the situation seems to come to an end. Filmed in a neorealistic, documentary style, the producers and the director worked with professional actors and mostly with miners who participated in the actual strike, as well as their families, as actors.
"Salt of the Earth" marked a milestone in the filmmaking of the labor and civil rights movement of workers and their wives and is recognized as one of the greatest American films of all time; Being selected for its historical value in 1992 for the National Cinematographic Record -NFR, by the Library of Congress. It became a public domain film after its copyright was not renewed in 1982.