Congress of Industrial Organizations

Congress of Industrial Organizations (CIO), association of industrial unions. Active from 1938 to 1955, it organized all workers in a plant into an industrial union (as opposed to a craft union, which focuses on one craft). The CIO organized both skilled and unskilled workers in steel, automotive, rubber, and other major industries. The CIO united with the American Federation of Labor (AFL) in 1955.

See also: American Federation of Labor and Congress of Industrial Organizations.