Mexican painter and graphic artist, labour organizer, and revolutionary. He was a prominent social realist and an outstanding member of the Mexican muralist movement of the 1930s. A lifelong political activist, who served as captain with the revolutionary army of Venustiano Carranza before 1919, his work championed his revolutionary ideals, as in Portrait of the Bourgeoisie (1939, Electrical Workers' Union, Mexico City). He was imprisoned 1960-64 for organizing a student riot.