- Jan 1 1st edition of New Rotterdam's Daily (3x per week)
- Jan 15 University of Notre Dame receives its charter in Indiana
- Jan 25 Recontre between Reps Weller & Shriver, US House of Representative
Historic Expedition
Feb 14 John C. Frémont and his party become the first Europeans to discover Lake Tahoe during his second expedition through the American West
- Feb 27 Dominican Republic gains independence from Haiti (National Day)
- Feb 28 12-inch gun aboard USS Princeton explodes, killing Secretary of State Abel P. Upshur, Secretary of the Navy Thomas Gilmer, and other high-ranking U.S. federal officials
- Mar 8 King Oscar I ascends to the throne of Sweden-Norway
- Mar 21 Origin of Baha'i Era-Baha'i calendar starts here (Baha 1, 1)
- Mar 21 The original date predicted by William Miller of Massachusetts for the return of Christ and the end of the world
- Mar 28 Jose Zorilla's "Don Juan Tenorio" premieres in Madrid
- Apr 12 Texan envoys sign Treaty of Annexation with the United States
Presidential Convention
May 1 Whig convention nominates Henry Clay as presidential candidate
Historic Communication
May 24 Samuel Morse taps out "What hath God wrought" in the world's first telegraph message
- May 25 1st telegraphed news dispatch is published in Baltimore Patriot
Historic Event
Jun 6 Young Men's Christian Association (YMCA) formed by George Williams in London
Historic Invention
Jun 15 Charles Goodyear patents the vulcanization of rubber
Historic Event
Aug 8 Brigham Young chosen as head of the Church of Jesus Christ of Latter-day Saints following the death of Joseph Smith
Historic Expedition
Oct 1 German explorer Ludwig Leichhardt departs Jimbour, the farthest outpost of settlement on the Queensland Darling Downs, to begin his exploration of Australia's Northern Territory from Moreton Bay to Port Essington
Election of Interest
Dec 4 James Knox Polk elected 11th US President