"Whose neck shall I stand on to make me feel superior, and what will I have out of it? I don't want anything lower than I am. I am low enough already. I want to rise and to push everything up with me as I go."

These are the words of Rosaura Quintero, a working-class woman, zinc miner’s wife and one of the central characters in Herbert Bieberman’s film Salt of the Earth (1954).  Based on a true story the film, which captures the valiant struggle of zinc miners on strike and the leadership of their wives, contains powerful lessons about the power of anti-sexist and anti-racist class fightback against the exploitive mining industry. However, few know the dramatic struggle that was waged to make the movie and to show it to broader audiences. That relatively unknown struggle is also the subject of  Biberman’s book Salt of the Earth: The Story of a Film.
The book reveals that Salt of the Earth, finished in 1953,was made by film workers who were blacklisted during the McCarthy era witch hunt due to their pro-communist politics or affiliations. The Hollywood film industry, not content with driving these workers out of jobs, did everything it could to stop Salt of the Earth. Despite the film’s radical working-class politics and the film maker’s ties to communism, both works conceal the most important lesson for the working class: workers need communism in order to rise above the misery of capitalism as Rosaura’s quote poignantly illuminates.
The story of getting this film made is ably told by Herbert Biberman, one of the Hollywood Ten sentenced to jail for refusing to testify before the House Un-American Activities Committee (HUAC). Hollywood began by refusing to give Biberman's Independent Productions Corporation (IPC) a union crew. This was done through Roy Brewer, International Representative of the stage workers union (IATSE). Brewer built his entire  career as a professional anticommunist in the labor movement (the Wikipedia article on him makes this crystal clear).
When IPC got a union crew anyway, Hollywood got Congressman Donald Jackson to denounce the filmmaking, starting an intense campaign to stop it. The lab that had developed the film refused to finish the job. In addition, armed vigilantes made their appearance, as Biberman describes:
From the other side of the ranch house a shot was fired. But it was not our guard; it was too far away. We waited. Another shot was heard coming from what seemed to be our side of the gully.
Besides describing the courageous struggle of individual miners and filmmakers at the height of McCarthyism, this book also shows how the rotten politics, infected with reformism and landslides back into capitalism, of the old Communist Party led  to the sellout of our  class struggle.
For example, the only thing Biberman and the leaders of the miners union could think to do was  call in the state police and dissolve in slobbering praise to the independent businessman who stand up to monopoly capitalism, like this:

America's chances for a democratic future were indeed good. America possessed one very meaningful attribute. It was so diverse in the composition of its human inhabitants . . . It also possessed businessmen who believed business was a way of making a living and not a cider-press to squeeze sovereignty out of a people. And it had a few businessmen who were so independently individualist that you attempted to organize them into a conspiracy at the peril of your life.

The main weakness of Salt of the Earth, both the movie and its accompanying book, is that it purposely omits the  communist message that workers will lose anything they win unless they fight for and win communism. Reformist politics will never free the working class.
Although the book is riddled with rotten politics it does not negate its good points. In addition to the inspiring struggle just to make the film, the book also explains  how the film was made, and this is perhaps the most important thing the modern communist moveщment can learn from it
The script for the movie was written by Michael Wilson, a blacklisted screenwriter. Wilson read the script to the miners, whose lives were laterportrayed in the film, and they made changes in it to make it true to themselves. For example:

Then he discussed another scene in the treatment. Just before the strike began Ramon, with part of his last pay check, knowing it was to be the last in quite a while, bought a bottle of whiskey. The men had no time to comment on the scene before the women objected. 'Our husbands are not drunkards,' they said. 'That goes out too,' said Mike. 'You see,' he said to us, ‘these are perfectly legitimate dramatic scenes and illustrations. In [a] script in which you are after a drama for its own sake, they'd be perfectly able. But we're dealing with something else.’

The miners were also given authority over the shooting of the film. What evolved was а film collective, made of professional Hollywood filmmakers and zinc miners. The collective was made up of Black, Latin, Native American and white workers. Biberman acknowledges the leadership given bу the mostly non-white miners. Speaking of Mrs. Molano, who plays Mrs. Salazar in the film, he writes:

One day, when I was rather beaten with problems, she came to me and said, “When you feel discouraged in your life afterwards, you come to us. We will always give you courage. Because we always have our backs against the walls, we have never а way to go but forward. We cannot afford to be downhearted. You will finish the picture.

In addition to the story of the struggle to make the film, the book also includes the screenplay, and stills from the movie.
When read with a critical eye—with a willingness to learn from an important struggle by communists of the past, to learn from their mistakes but also from their courage, antiracism, and perseverance—it is an inspiring story.
Herbert Biberman. “Salt of the Earth”, The Story of a Film. Illustrated edition. Harbor Electronic Publishing, 2003 (originally Beacon Press)