Siqueiros was born in 1898 in Chihuahua, Mexico. He was politically active throughout his life beginning with his involvement with the 1911 student strike at the Academy de San Carlos which he attended. He left school at the age of 16 to join the army. In 1919 he was awarded a government grant to study art in Europe and traveled to Madrid and Paris. In Paris he studied French Modernism and became involved with avant-garde artists including his lifelong friend Diego Rivera. It was in Paris that Siqueiros and Rivera developed the key philosophies that inspired the Mexican mural movement. In 1921 he published his Manifesto to the Artists in America in "Vida Americana". He returned to Mexico and began working with Rivera on a series of murals for the National Preparatory School in 1922. With Rivera, Siqueiros was a founding member of the Union of Technical Workers, Painters and Sculptors, and edited El Machete, the Union's publication.
In Mexico, Siqueiros became more politically active and involved in the Communist Party. He eventually served as party secretary and editor of the Communist newspaper. In 1930 his radical political involvement led to six months in exile in Taxaco, Mexico. He traveled to California in 1932 and painted murals for both public and private buildings. His best known commission of this period is a mural entitled America Tropical at the Plaza Art Center in downtown Los Angeles - this work was inmediately white-washed and is now being conserved by the Getty COnservation Institute.