Below is a list of unions affiliated with the AFL–CIO. Since the founding of the AFL in 1886, the AFL–CIO and its predecessor bodies have been the dominant labor federation (at least in terms of the number of member workers, if not influence) in the United States. As of 2014, the labor federation had approximately 12.7 million members. As of 2015, the AFL–CIO had 56 member unions.
Historical context
AFL forms
On December 8, 1886, the five-year-old Federation of Organized Trades and Labor Unions dissolved itself and became the American Federation of Labor (AFL). In its first half-century, a large number of trade and labor unions formed, joined the AFL, and either merged with other unions or ceased to exist. Many unions, particularly those in the construction industry and affiliated building trades, disaffiliated from the AFL for a variety of reasons. Some rejoined; some did not.
Throughout the AFL's history, jurisdictional issues caused a number of disaffiliations. In contrast to its early rival, the Knights of Labor, the AFL had adopted a policy of forming and admitting to membership (with a few limited, and notable, exceptions such as the United Mine Workers and Brewery Workers) only craft unions—unions whose membership was limited to workers with a single, narrow skill-set. But industrialization, with its emphasis on teams rather than individual workers manufacturing a product, disadvantaged craft unions in the drive to organize workers. A notable example was the effort to unionize the steel industry, where the Amalgamated Association of Iron and Steel Workers' adherence to craft unionism was a factor in the failure of many unionization drives. Some unions, including some large ones such as the Mine Workers, began advocating for a shift toward industrial unionism, where a union would organize all workers (regardless of skills) in a single company, market, or industry.
CIO splits, 1936–1955
The battle between the craft and industrial union philosophies led to a major membership loss for the AFL in 1935. In the first years of the Great Depression, a number of AFL member unions advocated for a relaxation of the strict "craft union only" membership policy but to no avail. In 1932, Mine Workers president John L. Lewis privately proposed to several like-minded union presidents that those unions which wanted to organize workers on an industrial basis form a group to begin to do just that. The group met informally for three years, and lost a number of jurisdictional battles over potential or newly organized workers. Eight national unions formally organized themselves into the Committee for Industrial Organization (CIO) on November 9, 1935. On September 10, 1936, the AFL suspended all 10 CIO unions (two more had joined in the previous year) and their four million members. In 1938, these unions formed the Congress of Industrial Organizations as a rival labor federation.
Over the next 20 years, both the AFL and CIO would lose member unions. The AFL would purge some member unions for advocating industrial unionism (notably the United Auto Workers and the United Rubber Workers) or for supporting political philosophies it felt were antithetical to its purposes. It also reaffiliated some unions which had joined the CIO. The CIO, for its part, expelled a number of unions in 1948 after concluding they had become infiltrated by Communists (at least one additional union disaffiliated rather than be expelled). Both the AFL and CIO would form new unions to compete with those they had expelled, with varying degrees of success.