Congress of Industrial Organizations (CIO), federation of affiliated North American industrial unions that originated in the mid-1930s within the American Federation of Labor (AFL), from which it was expelled in 1937. The AFL limited its membership to craft (skill) unions and refused to support the CIO’s organization of industrial (workplace) unions, which welcomed unskilled and semiskilled factory workers. The CIO operated independently until 1955, when it merged with the AFL to form the American Federation of Labor–Congress of Industrial Organizations (AFL-CIO).
As the Great Depression unfolded in the 1930s, the political environment in the United States became increasingly favourable to organized labour. Because of both ideological reasons and labour’s growing influence on the Democratic Party, the New Deal administration of Pres. Franklin D. Roosevelt proved to be a much more willing partner to the trade-union movement than its Republican predecessors had been. The rights to organize and to engage in collective bargaining that were gained by unions under the National Industrial Recovery Act (NIRA) of 1933 were further buttressed by the 1935 passage of the Wagner Act (officially, the National Labor Relations Act).
Against this backdrop, organized labour grappled with the pivotal matter of whether unions should be structured on craft or industry lines. At the American Federation of Labor’s 1935 convention, the issue came to a head. After an industry-based resolution, which stated that “in the great mass production industries…industrial organization is the only solution,” was defeated, a rift occurred in the organization. In November 1935 John L. Lewis, the president of the United Mine Workers of America (UMWA) union, and representatives of seven other unions (two more unions joined later) announced the formation of the Committee for Industrial Organization (CIO), with the intention of organizing workers in mass-production industries.
Lewis and the UMWA (supported principally by the Amalgamated Clothing Workers of America [ACWA] and the International Ladies’ Garment Workers’ Union [ILGWU]) initially provided the money and organizational framework for the mobilization and unionization of unskilled and semiskilled factory workers. Soon the CIO and the AFL were battling for leadership of American labour, often trying to organize the same workers. The CIO built momentum by introducing unionism into the previously unorganized steel, rubber, and automobile industries, reaching agreements with such large corporations as U.S. Steel and General Motors. But the process was often violent.
A dramatic “sit-down” strike against General Motors during the winter of 1936–37 convinced many unskilled workers that the motto “one shop, one union” could work and prompted other successful sit-down strikes to follow. The more traditional leaders of the AFL, who remained committed to limiting membership to craft unions, responded to CIO’s success by suspending the 10 dissident unions.
The committee formalized its break with the AFL when it held its first convention in Pittsburgh in November 1938. There it adopted a new name (Congress of Industrial Organizations) and constitution. It also elected Lewis as the organization’s president.
Lewis, a lifelong Republican, had crossed party lines to support Roosevelt for the presidency in 1932 and 1936, but he pledged to resign as CIO president if Roosevelt were to win a third term in 1940. When Roosevelt was reelected, Lewis stepped down and was replaced by Philip Murray, who had served under Lewis in the UMWA. During the following year the CIO organized the employees of the Ford Motor Company, steel companies (including Bethlehem, Republic, Inland, and Youngstown), and other big industrial corporations that previously had refused to sign agreements with it.
Having notched these significant unionizing victories, the CIO unions still had to prove that they had the wherewithal to enforce the contractual provisions of workplace due process and to discipline a turbulent rank and file. Under close wartime regulation during World War II, they did so, and institutional relations between the CIO and corporate industry were solidified. After a strike wave tested the parameters of this relationship in the immediate postwar period, there ensued a system of industry-wide collective bargaining that endured for the next 40 years. In 1955 the CIO merged with the AFL to form the AFL-CIO.