twentieth century

Socialism/Marxism/Bolshevik Revolution/Communism
WWI
Einsteinian and quantum revolutions in physics
end of the domination of the old empires (European, Ottoman)
Freudian revolution in psychology
corporate-managerial revolution in commerce
Great Depression
welfare statism
Nazis
WWII
existentialism revolution in philosophy
Cold War / Berlin Wall
American cultural hegemony
Cuban missile crisis
Vietnam War
technosphere expansion
environmentalist critique
youth rebellion / counterculture
Reagan/Thatcher reaction
collapse of Communism
capitalist globalization
dollar hegemony / US geopolitical dominance