U.S. History 1877-2008 By sarah.stricklen Period: 1776 to 1860 Early American History Period: 1860 to 1877 Civil War Reconstruction Period: 1877 to 1900 Gilded Age Period: 1890 to 1920 The Progressive Era Period: 1898 to 1910 Imperialism Period: 1914 to 1918 World War 1 Period: 1920 to 1929 Roaring Twenties Period: 1929 to 1939 Great Depression Period: 1939 to 1945 World War 2 1945 United Nations Formed Period: 1945 to 1960 Early Cold War 1948 Berlin Airlift 1949 NATO established 1950 Korean War Period: 1950 to 1970 Civil Rights Era 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 1991 End of the Cold War Period: 1990 to 2008 1990s-21st Century