American Federation of Labor AFL-CIO

The American Federation of Labor and Congress of Industrial Organizations (AFL–CIO) is the largest federation of unions in the United States. It is made up of fifty-five national and international unions, together representing more than 12 million active and retired workers. The AFL–CIO engages in substantial political spending and activism, typically in support of Democrats and liberal or progressive policies.

The AFL–CIO was formed in 1955 when the AFL and the CIO merged after a long estrangement. Membership in the union peaked in 1979, when the AFL–CIO had nearly twenty million members. From 1955 until 2005, the AFL–CIO's member unions represented nearly all unionized workers in the United States.