- 1841 William H. Harrison, "Old Tippecanoe," becomes 9th President on Mar 4.
Catches cold at inauguration and dies Apr 4--one month after taking office.
John Tyler becomes 10th President on Apr 6.
- 1841 Russia sells Fort Ross in California to John Sutter.
- 1844 Samuel F. B. Morse opens telegraphic link between Baltimore and D.C.
- 1845 Florida admitted as 27th state on Mar 3.
- 1845 James K. Polk becomes 11th President on Mar 4.
- 1845 U.S. Naval Academy opens at Annapolis, Maryland.
- 1845 Texas annexed triggering war with Mexico. Admitted: 28th state, Dec 29.
- 1845 Johnny Appleseed (John Chapman) dies, goes to big orchard in the sky.
- 1846 Large crack in Liberty Bell gets too bad to permit ringing.
- 1846 Smithsonian Institution founded with gift from estate of James Smithson.
- 1846 Potato famine in Ireland. Many flee to America for survival.
- 1846 Iowa admitted as 29th state on Dec 28.
- 1847 Brigham Young leads his followers into Salt Lake City, Utah, area.
- 1847 American troops fight their way into the Halls of Montezuma in Mexico.
- 1848 Wisconsin admitted as 30th state on May 29.
- 1848 Treaty of 1848 gains CA, NM, AZ, NV, UT, parts of CO and WY for the Union.
- 1848 Cornerstone laid for the Washington Monument.
- 1849 Zachary Taylor becomes 12th President on Mar 4. Dies Jul 9, 1850.
- 1849 Gold discovered at Sutter's mill in California. Gold-rush begins.