Salt of the Earth was written by Michael Wilson, directed by Herbert J. Biberman, and produced by Paul Jarrico, all of whom had been blacklisted during the Red scare of the 1950s. Its plot centers on a long and difficult strike, based on the 1951 miners’ strike against the Empire Zinc Company in New Mexico.

The movie was financed by the International Union of Mine, Mill and Smelter Workers and denounced at the time by the United States House of Representatives for its communist sympathies. In 1992 the Library of Congress selected the film for preservation in the US National Film Registry. Thanks to its 3½ (of 4) stars from Leonard Maltin and a solid IMDb user rating, it was also selected to be 46th in the Internet Archive Top 100.