- 1850 The Plague: Pandemic strikes the world. Millions die.
- 1850 Taylor dies: Millard Fillmore becomes 13th President on Jul 9.
- 1850 The Compromise of 1850; on the slave debate for the territories.
- 1850 California admitted as 31st state on Sep 9.
- 1850 Fugitive Slave Act, Sep 18, requires return to owners.
- 1851 Harriet Beecher Stowe's Uncle Tom's Cabin published.
Adds to slavery tensions.
- 1851 Isaac Singer granted a patent for his sewing machine.
- 1852 Death of Daniel Webster, October 24. Did he really say, "... have I ... said anything unworthy of Daniel Webster?"
- 1853 Franklin Pierce becomes 14th President on Mar 4.
- 1853 Jefferson Davis appointed Secretary of War by President Pierce.
- 1853 Gadsden Purchase brings some Mexican territory into U.S.A.
- 1853 Commodore Matthew Perry opens trade routes with Japan, July 14.
- 1854 Kansas - Nebraska Act. Provides springboard for Abe Lincoln.
- 1854 Republican Party formed under John Fremont in Ripon, WI, 28 February.
- 1855 Soo Canal opens upper Great Lakes to commercial navigation.
- 1855 Longfellow uses name of Six Nation's heroine, Hiawatha, in mythical poem.
- 1856 Western Union Telegraph Co. established in Cleveland.
- 1856 Cocaine extracted from cocoa leaves, but has no legitimate use.
- 1857 James Buchanan becomes 15th President on Mar 4.
- 1857 Dred Scott decision handed down by Supreme Court, March 6.
- 1857 Transatlantic cable begins; used briefly in 1858. Replaced in 1866.
- 1858 Minnesota admitted as 32nd state on May 11.
- 1858 Abraham Lincoln warns that "A House Divided Against Itself Cannot Stand."
- 1859 Oregon admitted as 33rd state on Feb 14.
- 1859 Harpers Ferry armory raided by abolitionist John Brown. Colonel Robert E. Lee commands U.S. Army troops in response.
- 1859 Drake puts down first oil well in U.S.A., Titusville, PA.