Industrial Workers of the World

The Industrial Workers of the World (IWW), whose members are nicknamed "Wobblies", is an international labor union founded in Chicago, Illinois, United States, in 1905. Its ideology combines general unionism with industrial unionism, as it is a general union, subdivided between the various industries which employ its members. The philosophy and tactics of the IWW are described as "revolutionary industrial unionism", with ties to socialist, syndicalist, and anarchist labor movements.

In the 1910s and early 1920s, the IWW achieved many of its short-term goals, particularly in the American West, and cut across traditional guild and union lines to organize workers in a variety of trades and industries. At their peak in August 1917, IWW membership was estimated at more than 150,000, with active wings in the United States, the United Kingdom, Canada, Australia and New Zealand. However, the extremely high rate of IWW membership turnover during this era (estimated at 133% between 1905 and 1915) makes it difficult for historians to state membership totals with any certainty, as workers tended to join the IWW in large numbers for relatively short periods (e.g., during labor strikes and periods of generalized economic distress).