U.S. History: 1887-2008 By samuelhsteele Period: 1776 to 1860 Early American History Jul 4, 1776 Declaration of Independence Well... I think we all know what this one is. Sep 17, 1787 Bill of Rights Ratified 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 (The Great War) Period: 1920 to 1929 Roaring Twenties Period: 1929 to 1939 The Great Depression Period: 1939 to 1945 World War II Period: 1945 to 1960 Early Cold War Period: 1950 to 1970 Civil Rights Era Period: 1954 to 1976 Vietnam War 1962 Cuban Missile Crisis 1965 Medicare and Medicaid Established 1968 Tet Offensive Period: 1970 to 1991 End of the Cold War 1971 Pentagon Papers Leaked Mar 23, 1971 26th Amendment Ratified Lowered voting age from 21 to 18 1975 Fall of Saigon, End of Vietnam War Period: 1990 to 2008 1990s-21st Century (Modern Era)