San Francisco Earthquake - 1906
Triangle Shirtwaist Factory Fire - 1911
Sinking of the Titanic - 1912
World War I: 1911-1918
Eastland Disaster - 1915
Spanish Flu - 1918
Great Depression (Overview, Dust Bowl, Stock Market Crash)
World War II: 1939-1946 (Overview, Nazi Occupation, Pearl Harbor, Atomic Bombs)