Their employer refuses them safety helpers, so Chicano miners of the International Union of Mine, Mill, and Smelt Workers strike. When the mine owner cites the Taft-Hartley Act and gets an injunction, the miners' wives replace them at the picket. Told by Esperanza (Revueltas), wife of union foreman Ramon (Chacón), the movie is less well-known than the story of how it was made. Its creative team - director Biberman, co-writer Wilson, and producer Paul Jarrico - were blacklisted as communists. Continually harassed by government and studios, they had to complete "Salt" in secret. Revueltas, one of the cast's few professional actors, was deported, so shooting resumed in Mexico. The completed picture was banned in the U.S. until the 1970s, after one screening in one New York theater.

Revueltas, Geer (as the sheriff), Williams (as Hartwell), and Clinton and Virginia Jencks (as Frank and Ruth Barnes) were professional actors; the rest were union workers whose strike inspired the story. Events and the miners' lives and culture are shown faithfully. Given its production, the film is wonderful, emotionally-dynamic, and omits gratuitous romance, melodrama, and condescension. Revueltas is great, conveying shyness, strength, and heroism. Watching this 1954 movie, we see that although the decade was highly conventional and reactionary, it had depths and diversity of thought.

Another fascinating aspect of the movie is its depiction of gender issues. The miners refuse to demand home-heating or proper sanitation; those seem too unimportant until their wives fill the picket line, and the men must do the wash and care for children. Then they see how hard their wives' daily lives are. At first, the men oppose their wives' striking; Ramon even yells at Esperanza. Her feminist reply makes the viewer believe enlightened opinions of sizable minorities from that time did exist, but were hushed by the film industry and subsequent decades' history books.

Salt of the Earth repeats the old cry, "People united can't be defeated." A modest, engaging social drama, Salt is brilliant in contrast to the timidity that surrounded it. Such works can never be "ordinary."