The document discusses Marxism and the rise of socialist movements in Europe in the late 19th century. It describes how socialist parties grew rapidly after 1871 and united internationally, forming the First International in 1864 led by Marx. The Second International, a federation of national socialist parties, lasted from 1864 to 1914. While Marx predicted a violent proletariat revolution, unions became gradually legalized and living standards rose, making workers less revolutionary. Revisionist socialists believed in achieving socialism through reform within capitalist systems using unions and other legal means, rather than violent revolution. By the late 19th century, socialist movements in each country became more nationalist and distinct from one another.