U.S. History: 1877-2008 By Chris.Young 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 1 Oct 24, 1945 United Nations Formed Jun 24, 1948 Berlin Airlift Apr 4, 1949 NATO Established Period: Jun 25, 1950 to Jul 27, 1953 Korean War Mar 6, 1951 Rosenburg Trials Nov 1, 1952 First H Bomb Detonation Mar 26, 1953 Jonas Salk Created The Polio Vaccine Period: 1955 to 1956 Montgomery Bus Boycott after Rosa Park's arrests 1957 Little Rock Nine integrated into an all-white school in Little Rock Oct 4, 1957 USSR Launches Sputnik 1961 Bay of Pigs invasion In Cuba 1961 Berlin Wall built to prevent people from leaving communist East Berlin 1962 Cuban Missile Crisis 1963 Martin Luther King's "I Have a Dream Speech" at March on Washington 1963 John F. Kennedy is assassinated in Dallas, TX 1965 Medicare and Medicaid established 1968 Tet Offensive 1968 Martin Luther King is assassinated 1969 First Man on the Moon 1971 Pentagon Papers Leaked 1975 Fall of Saigon, marks the end of the vietnam war