Voices from the Dust Bowl: The Charles L. Todd and Robert Sonkin Migrant Worker Collection, 1940-1941 (from the Library of Congress)
The Samuel Gompers Papers: A Documentary History of the American Working Class (Sponsored by the University of Maryland-College Park, the National Historical Publications and Records Commission, the National Endowment for the Humanities, and the George Meany Memorial Archives
United Farm Workers history page
United Auto Workers history page
Chinese laborers in the U.S.: Chinese-American History Timeline
Chinese laborers in the U.S.: Railroad workers in Tucson