Socialist Organizer is the U.S. section of the Fourth International, and works with comrades globally.
The First International, also known as the International Workingman’s Association, founded by Marx, Engels, and many others in 1864, aimed to bring together under one organizational umbrella all the existing organizations of the workers’ movement, whether trade union or political (socialist, anarchist, Prodhounist, etc.). After the defeat of the first workers’ revolution in history, the Paris Commune of 1871, the First International was dissolved.
The Second International, also known as the Socialist International, founded by Engels and his co-thinkers in 1889, consisted of mass parties based on a socialist program, in which both reformist and revolutionary currents co-existed. Under the pressures of the tremendous capitalist expansion in the pre-war years, the parties of the Second International became more and more co-opted into the status quo and in 1914 they definitively betrayed the interests of the working class by supporting World War I.
The Bolshevik Party led by V.I. Lenin in Russia belonged to the Second International until 1914, but upheld the program of revolutionary Marxism and led the Russian Revolution of 1917 to victory.
The Third International, also known as the Communist International, was founded in 1919 by V.I. Lenin, Leon Trotsky, and their allies throughout the world with the goal of building revolutionary parties in each country of the world to lead a world socialist revolution. Millions rallied to the banner of the Third International, but the failure of the revolutions in Italy (1919-20), Germany (1918-23), and China (1925-27) led to the isolation of the Russian Revolution, the rise of the dictatorial Stalinist bureaucracy in the 1920s, and the subsequent degeneration of the Third International in Stalin’s hands.
The Fourth International, founded by Leon Trotsky and his co-thinkers in 1938, upheld the central strategic goal of building mass revolutionary socialist parties to lead a world revolution. But for decades the Socialist and Communist parties remained hegemonic in the workers’ movement, and the Fourth International remained isolated from the working class. The Fourth International suffered a dislocating split in 1953 but was eventually re-founded in 1993, in the new context opened by the fall of the Soviet Union in 1989-91. Today, the Fourth International has sections in over 45 countries and is a growing force.