In 1922, Siqueiros returned to Mexico City to work as a muralist for Álvaro Obregón's revolutionary government. The then Secretary of Public Education José Vasconcelos made a mission of educating the masses through public art, and hired scores of artists and writers to build a modern Mexican culture. Siqueiros, Rivera and José Orozco worked together under Vasconcelos, who supported the muralist movement by commissioning murals for prominent buildings in Mexico City. Still, the artists working at the Preparatoria realized that many of their early works lacked the "public" nature envisioned in their ideology. In 1923 Siqueiros helped found the Syndicate of Revolutionary Mexican Painters, Sculptors and Engravers, which addressed the problem of widespread public access through its union paper, "El Machete". That year the paper published – "for the proletariat of the world" – a manifesto, which Siqueiros helped author, on the necessity of a "collective" art, which would serve as "ideological propaganda" to educate the masses and overcome bourgeois, individualist art.