U.S. History: 1887-2008 By MaxwellBurrows Period: 1776 to 1860 Early American History Period: 1860 to 1877 Civil War / Reconstruction Period: 1877 to 1900 The Gilded Age Period: 1898 to 1910 Imperialism Period: 1900 to 1920 The Progressive Era Period: 1914 to 1918 WW1 Period: 1920 to 1929 Roaring 20s Period: 1929 to 1939 Great Depression Period: 1939 to 1945 WW2 1945 United Nations Formed Period: 1945 to 1960 Early Cold War 1947 22nd Amendment 1947 Truman Doctrine 1948 Marshall Plan 1948 Berlin Airlift 1949 NATO Established Period: 1950 to 1970 Civil Rights Era Period: 1950 to 1953 Korean War 1951 Rosenbergs Trial 1952 First H-Bomb Detonated by the U.S.A. Period: 1954 to 1976 Vietnam War 1955 Jonas Salk Invents the Polio Vaccine 1957 USSR Launches Sputnik 1962 Cuban Missile Crisis 1964 Gulf of Tonkin Resolution 1965 Medicare and Medicade Established 1968 Tinker v. Des Moines 1968 Tet Offensive Period: 1970 to 1991 End of Cold War 1971 Pentagon Papers Leaked 1971 26th Amendment 1973 War Powers Act 1975 Fall of Saigon Period: 1990 to 2008 90s / 21st century