Period 1 1491–1607 - Pre-columbian societies to Jamestown (Early European Expansion)
Period 2 1607-1754 - Jamestown to French and Indian War (Colonial Development)
Period 3 1754-1800 - French and Indian War to Jefferson (Revolution & New Republic)
Period 4 1800-1848 - Jefferson to Mexican-American War (Democracy & Expansion)
Period 5 1844-1877 - Polk to End of Reconstrution (Civil War & Reconstruction)
Period 6 1865-1898 - Reconstruction to Spanish-American War (Industrialization)
Period 7 1890-1945 - Closing of Fronteir to World War One (Progressivism, Great Depression, WWII)
Period 8 1945-1980 - End of World War Two to Ronald Reagan (Cold War & Civil Rights)