Before Columbus (525 million years ago to 1492)
New world (1492 to mid-eighteenth century)
Let freedom ring (1760s to 1820s)
Young nation (late eighteenth century to 1850s)
Sea to shining sea (1800 to 1850s)
A house divided (1850 to 1865)
Manifest destiny (1845 to early twentieth century)
Industrial revolution (1865 to early twentieth century)
Modern nation (1870s to 1929)
Great Depression (1929 to 1940)
Greatest generation (1941 to 1945)
New frontiers (1950s to 1980s)
Civil rights (1947 to now)
Pop culture (Mid-twentieth century to now)
Digital age (1945 to now)
New millennium (2000 to the future).
