In the early 1900s, the legendary Joe Hill emigrates with his brother to the United States. But after a short time, he loses touch with his brother. Joe gets a few jobs but is struck by all the injustice and tragedy going on. He becomes active in the forbidden union IWW, a union for workers without trades. It is forbidden to demonstrate and to speak in public but Joe gets around that by singing his manifests with the Salvation Army. He manages to get more and more people to go on strike with him but he also makes powerful enemies doing that. Finally he gets connected with a murder and during the trial he fires his lawyer and takes upon himself to become his own defender.

En 1902, deux immigrants suédois, Joel et Paul Hillstrom, arrivent aux Etats-Unis. Ils doivent faire face à une langue nouvelle et à l'effroyable pauvreté qui règne dans les quartiers de l'East Side à New-York. Paul quitte la ville, Joel y reste, amoureux d'une jeune Italienne. Mais la liaison est de courte durée. Rien ne le retenant à New-York, Joel, devenu Joe Hill, se met en route vers l'Ouest pour retrouver son frère...