All of the harassment depicted in the movie really happened to various women. Two women were trapped in porta-potties that were tipped while they were inside. Miners ejaculated onto female miner's clothes in lockers three times. Many more incidents of harassment occurred than could be shown in a 2-hour movie.
Josey Aimes is based on Lois Jenson, who started working in the mines in 1975 and endured 13 years of harassment before filing her first lawsuit. Jenson v. Eveleth Mines was settled in 1998, 10 years after it was first filed and over 20 years after the harassment began.
According to the book Class Action, the rape that produced Lois Jenson's son occurred after high school. In real life, Jenson put her daughter up for adoption as a toddler because she was overwhelmed trying to raise two children on her own, in low paying jobs. Her father supported her decision to work in the mine because he thought it would help her provide for her son.
In real life there were multiple trials, not just the one depicted in the movie. In the first trial, Jenson and two other women petitioned to have the lawsuit designated a class action, on behalf of all women working in the mines. The judge certified a class action including only the hourly female mine workers, not the salaried female officer workers who were also sexually harassed. The second trial established that sexual harassment occurred and that the company was liable for it. The third trial was to determine the amount of monetary damages each woman suffered. The fourth trial, in the 8th Circuit Court of Appeals, reversed the award of damages. The company settled just before the fifth trial started, paying each plaintiff an average of $233,000. By the time Jenson received compensation from the company in 1999, her children were grown and she was too disabled to work.
Actor Bill Nighy stated during a Q&A session at the British Film Institute in London in 2010 that in his opinion he regards Richard Jenkins' performance in this film as one of the finest in motion picture history.
Charlize Theron spent time at the homes of some of the female miners to get to know them personally. "I spent as much time as I possibly could with the women. They don't wallow in self pity, they're survivors."
Charlize Theron wanted to react to the crowd in the union meeting without rehearsal so it would feel authentic. "That was, I think in my entire career, the most devastating thing I've ever encountered."