U.S History 1887-Present Day By Patrik H. Period: 1776 to 1860 Early American History Period: 1860 to 1877 Civil War/Reconstruction Period: 1877 to 1900 The Gilded Age Period: 1890 to 1920 The Progressive Era Period: 1898 to 1910 Imperialism Period: 1914 to 1918 World War I Period: 1920 to 1929 Roaring Twenties Period: 1929 to 1939 Great Depression Period: 1939 to 1945 World War II 1945 United Nations formed Period: 1945 to 1960 Early Cold War Containment. Arms Race/ Space Race. The Union of Soviet Socialist Republics. Communism. Domino Theory 1947 Truman Doctrine Mar 21, 1947 22nd Ammendment 1948 Berlin Airlift 1948 Marshall Plan 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. Period: 1954 to 1976 Vietnam War 1955 Jonas Salk Invests in the Polio Vaccine 1957 USSR Launches Sputnik 1970 Kent State University shooting Period: 1970 to 1991 End of the Cold War 1974 Watergate Scandal, which leads to Nixon's resignation 1978 Camp David Accords 1979 Three Mile Island Disaster Period: 1979 to 1981 Iran-Hostage Crisis Period: 1985 to 1987 Iran Contra Affair Period: 1990 to 2008 1990s-21st Century