The Communist Manifesto (1848)
Marx and Engels published the Communist Manifesto in 1848, the same year revolutions swept Europe. The pamphlet ended with the famous lines: "Let the ruling classes tremble at a Communist revolution. The proletarians have nothing to lose but their chains. They have a world to win. Working men of all countries, unite!"
Das Kapital (1867-1894): Marx's major theoretical work, a multi-volume analysis of capitalism's structure, contradictions, and predicted demise.
Why Marxism matters for the rest of the course: Marxism becomes the basis of the Russian Revolution (Unit 10.5), the Chinese Revolution under Mao (Unit 10.6), Cold War conflicts (Unit 10.6 again), and decolonization movements (Unit 10.7). Maria should treat the basic Marxist vocabulary (bourgeoisie, proletariat, class struggle, surplus value, dictatorship of the proletariat) as essential vocabulary for the rest of the course, even when the topic is not formally about communism.