1851 in the United States
Events from the year 1851 in the United States.
- President: Millard Fillmore (W-New York)
- Vice President: vacant
- Chief Justice: Roger B. Taney (Maryland)
- Speaker of the House of Representatives: Howell Cobb (D-Georgia) (until March 4), Linn Boyd (D-Kentucky) (starting December 1)
- Congress: 31st (until March 4), 32nd (starting March 4)
- January 15 – Christian Female College, now Columbia College, receives its charter from the Missouri General Assembly.
- January 23 – The flip of a coin determines whether a new city in the Oregon Territory is named after Boston, Massachusetts, or Portland, Maine, with Portland winning.
- January 28 – The Illinois General Assembly grants a charter to create Northwestern University.
- April 9 – San Luis, the oldest permanent settlement in the state of Colorado, is founded by settlers from Taos, New Mexico.
- April 28 – Santa Clara College is chartered in Santa Clara, California.
- May 6 - John Gorrie of Apalachicola, Florida was granted Patent No. 8080 for a machine to make ice
- May – August – Great Flood of 1851 causes extensive damage in the Midwest, town of Des Moines virtually destroyed.
- May 15 – Alpha Delta Pi Sorority, the first secret society for women, is founded at Wesleyan College in Macon, Georgia.
- July 10 – The University of the Pacific is chartered as California Wesleyan College in Santa Clara, California.
- August 1 – Virginia closes its Reform Constitutional Convention deciding that all white men have the right to vote.
- August 22 – The yacht America of the New York Yacht Club wins the first America's Cup race, off the coast of England.
- September 15 – Saint Joseph's University is founded in Philadelphia, Pennsylvania.
- September 18 – The New York Times is founded.
- October 15 – The City of Winona, Minnesota is founded.
- October – Sojourner Truth delivered her Aint I a Woman? speech in 1851 at the Women's Rights Convention in Akron, Ohio
- November 13 – The Denny Party lands at Alki Point, the first settlers of what later becomes Seattle, Washington.
- November 14 – Herman Melville's novel Moby-Dick; or The Whale is published in the U.S. by Harper & Brothers, New York, after being first published on October 18 in London by Richard Bentley, in 3 volumes as The Whale.
- December 29 – The first YMCA opens in Boston, Massachusetts.
- Western Union is founded as the New York and Mississippi Valley Printing Telegraph Company.
- House sparrows first released in the U.S., in Brooklyn.
- Stephen Foster's minstrel song "Old Folks at Home" is first published.
- California Gold Rush (1848–1855)
- January 24 – Marcus A. Smith, U.S. Senator from Arizona from 1912 to 1921 (died 1924)
- May 21 – Moses E. Clapp, U.S. Senator from Minnesota from 1901 to 1917 (died 1929)
- May 29 – Fred Dubois, U.S. Senator from Idaho from 1891 to 1897 and from 1901 to 1907 (died 1930)
- August 12 – Frank O. Briggs, U.S. Senator from New Jersey from 1907 to 1913 (died 1913)
- August 14 – Doc Holliday, gunfighter and gambler (died 1887)
- December 9 – Thomas H. Paynter, U.S. Senator from Kentucky from 1907 to 1913 (died 1921)
- December 10 – Melvil Dewey, born Melville Dewey, librarian (died 1931)
- January 17 – Thomas Lincoln, farmer and father of the President of the United States Abraham Lincoln (born 1778)
- January 27 – John James Audubon, naturalist and illustrator (born 1785 in Saint-Domingue)
- January 31 – David Spangler Kaufman, Congressman from Texas (born 1813)
- February 3 – Benjamin Williams Crowninshield, Congressman from Massachusetts, secretary of U.S. Navy (born 1772)
- May 3 – Thomas Hickman Williams, U.S. Senator from Mississippi from 1838 to 1839 (born 1801)
- May 22 – Mordecai Manuel Noah, Jewish playwright, diplomat, journalist and utopian (born 1785)
- July 6 – Thomas Davenport, electrical engineer (born 1802)
- August 24 – James McDowell, politician (born 1795)
- September 10 – Thomas Hopkins Gallaudet, minister, educator, co-founder of the first permanent school for the deaf in North America (born 1787)
- September 11 – Sylvester Graham, nutritionist and inventor (born 1794)
- September 14 – James Fenimore Cooper, historical novelist (born 1789)
- September 24 – Lucius Lyon, U.S. Senator from Michigan from 1843 to 1845 (born 1800)
- November – Willis Buell, politician and portrait painter (born 1790)
- Media related to 1851 in the United States at Wikimedia Commons