Because of the presence of the ailing James Cagney, in what became his final big screen appearance, the movie was officially exempted from the long-running actors' strike of the early 1980s. It was the only production to receive that honor.
James Cagney had been advised by his doctors and caregivers that making a film at this point in his life was very important for his health. The actor never flew, so he and his wife took an ocean liner to London, where his scenes were filmed. Despite his numerous infirmities, he stayed on-set during his fellow actors' close-ups to give them line readings.
Jack Nicholson had to drop out of the film less than a month before filming began, leaving the producers without a name star. Director Milos Forman recruited James Cagney, who he had met the year before at a private dinner in Connecticut. He offered Cagney any part he wanted, including (facetiously) Evelyn Nesbitt.
A ten-minute sequence on the Lower East Side featuring real-life social activist Emma Goldman was cut from the final print. In the sequence, Goldman takes Evelyn Nesbitt back to her apartment, explains her misgivings about women wearing restrictive undergarments, removes them from Nesbitt and tries to recruit her for the Socialist cause. During the scene, a voyeuristic younger brother followed them into the building and secretly watches Nesbitt undress.
According to Director Milos Forman, James Cagney initially agreed to play New York City Police Commissioner Rhinelander Waldo on two conditions: he would not sign a contract of any kind, and he reserved the right to change his mind and quit the film until three days before shooting began on his scenes.
O.J. Simpson lobbied hard for the role of Coalhouse Walker, Jr. As presented in the documentary O.J.: Made in America (2016), Simpson saw himself in that role, but Director Milos Forman decided to go with Howard E. Rollins, Jr., a former teacher who got his first break in films with this role.
Of the movie's two-hour thirty-five-minute running time, 49 minutes feature music. The soundtrack album includes 13 minutes of music unheard in the movie. That implies that Randy Newman wrote over an hour's worth of music for the movie, only to have it cut down. One song, "Change Your Way", was supposed to be sung by Scatman Crothers for the opening credits, but the scene was never shot. The song can be heard on the soundtrack album, sung by Newman. The "Denouement" cue clocks on the soundtrack at five minutes and 43 seconds. Only one minute and 43 seconds ended up in the final cut.
Coalhouse Walker, Jr., and his mistreatment by the fire chief, is a remake the 19th-century German novella "Michael Kohlhaus" by Heinrich Wilhelm von Kleist. In the novel, Kohlhaas is a Brandenburg horse dealer who is made to pay a "toll" by a member of the nobility, who then destroys his horses. Kohlhaas ultimately takes justice into his own hands after his Model T is destroyed. Von Kleist's story was a remake of a 16th-century story. It was also made into the film Michael Kohlhaas - Der Rebell (1969).
Milos Forman originally wanted E.L. Doctorow to collaborate on the screenplay, but the novelist thought that a feature film could not do justice to his epic novel, and believed that it should be done as a ten-part television miniseries. Doctorow did not participate in the development of the screenplay.
Mariclare Costello spent three weeks filming as Emma Goldman in a sequence that was cut from the film. Milos Forman wanted to keep her part in the film, but Producer Dino De Laurentiis thought it slowed the movie down. E.L. Doctorow, the novel's author, was brought in to break the tie. Doctorow agreed with De Laurentiis, and the footage was cut. The sequence is included as an extra on the DVD release.