US history 1887-2008 By traveon.conell Period: 1776 to 1860 Early American History Period: 1860 to 1877 Civil War/Reconstruction Period: 1877 to 1900 The Gilded Age (1877-1900) Period: 1890 to 1920 The Progressive Era (1890-1920) Period: 1898 to 1910 Imperialism (1898-1910) Period: 1914 to 1918 World War I Period: 1920 to 1929 Roaring Twenties Period: 1929 to 1939 Great Depression (1929-1939) Period: 1939 to 1945 World War II (1939-1945) 1945 United Nations formed Period: 1945 to 1960 Early Cold War (1945-1960) 1947 Truman Doctrine U.S. policy that gave military and economic aid to countries threatened by communism 1948 Berlin Airlift 1948 Marshall Plan program to help European countries rebuild after World War II 1949 NATO established 1950 Korean War Period: 1950 to 1970 Civil Rights Era (1950-1970) 1951 : Rosenbergs trial 1952 First H-Bomb detonated by the United States Period: 1954 to 1976 Vietnam War 1955 Jonas Salk invents the Polio Vaccine 1957 : USSR launches Sputnik Period: 1970 to 1990 End of the Cold War (1970-1991) Period: 1990 to 2008 1990s-21st Century (1990-2008)