A leading member of the Mexican muralist movement and a technical innovator of fresco and wall painting. The collection consists
almost entirely of manuscripts, some in many drafts, others fragmentary, the bulk of which date from the mid-1930s, when Siqueiros
traveled to Los Angeles, New York, Buenos Aires, and Montevideo, returning intermittently to Mexico City. A significant portion
of the papers concerns Siqueiros's public disputes with Diego Rivera; there are manifestos against Rivera, eye-witness accounts
of their public debate, and newspaper coverage of the controversy. There is also material regarding the murals
Mexico Actual and
Ejercicio Plastico, including one drawing and a few photographs. The Experimental Workshop in New York City is also documented.