From 1910 to 1927 workers in the Mexican cotton textile industry took advantage of the larger surrounding revolution to create a revolution of their own. Based on a significant and persistent challenge to workplace authority, millhands radically transformed the labour regime in Mexican industry. Although owners combated the workers' rebellion, they never inflicted a decisive defeat. As a consequence, the conditions of work in Mexican mills improved dramatically. Among the advancements workers fought for, and obtained, were a sharp reduction in the working day from fourteen hours to eight, mandated medical care for work-related accidents and illnesses and union control of hiring and firing. The latter included the union shop and a system of tripartite boards that made it virtually impossible to fire workers who enjoyed union support. The new labour regime reflected changes in the formal and informal institutions of work, but its final institutionalisation empowered unions more than the rank and file workers who fought to change the social relations of work.