[2] Born in Los Angeles' Boyle Heights neighborhood, Soto served as a bombardier in the Army Air Corps[3] in the South Pacific during World War II.

Afterward, he helped organize the GI Forum, a foundation for Hispanic American veterans.

[4] Soto was a driving force behind the establishment of cityhood for La Puente, California, a formerly unincorporated area of East Los Angeles.

Soto represented the La Puente area in the California Assembly for two two-year terms, from 1962 to 1966.

[4] He later was appointed by President Lyndon B. Johnson to help set up economic development and job training programs in East Los Angeles.