In Liberation of the Peon, Rivera developed a harrowing narrative of corporal punishment. A laborer, beaten and left to die, is cut down from a post by sympathetic revolutionary soldiers, who tend to his broken body. Peonage—a system of indentured servitude established by Spanish colonizers, under which natives were forced to work the land—persisted in Mexico into the 20th century. The mural offers the injustice of earlier social and economic conditions as a rationale for the Mexican Revolution.