- 1820: The Missouri Compromise
- 1825: The Erie Canal is opened.
- 1830s: The Second Great Awakening.
- Indian Removal Act.
- Baltimore and Ohio Railroad begins operation.
- 1831: The Liberator begins publication.
- Nat Turner Rebellion
- Cyrus McCormick invents the reaper.
- 1831-1838: The Trail of Tears--Southern Indians are removed to Oklahoma.
- 1836: The Gag Rule.
- 1837: US recognizes the Republic of Texas.
- Oberlin College enrolls its first women students.
- 1843: Oregon Trail opens.
- 1845: Annexation of Texas
- 1846: Elias Howe invents the sewing machine.
- 1846-1848: Mexican-American War.
- 1848: Gold is discovered at Sutter's Mill in California.
- 1850: Compromise of 1850.
- 1853: Commodore Matthew Perry opens Japan to US trade.
- 1854: The Kansas-Nebraska Act
- 1857: The Dred Scott decision.
Douglass: Anti-Slavery Movement