Complex sentence: Four events in 1968 turned the American student movement into self-proclaimed Marxist-Leninist revolutionaries: the Viet Cong's Tet Offensive; the student sit-in at Columbia University; the near-revolution in France; and the Democratic National Convention in Chicago.
Split into simpler sentences: Four events in 1968 turned the American student movement into self-proclaimed Marxist-Leninist revolutionaries. The first event was the Vietcong's Tet offensive; the student sit-in at Columbia University; the near-revolution in France, and the Democratic Convention in Chicago.