Federal government edit

• 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–March edit

• January 15 – Christian Female College, later 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–June edit

• 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–August – The Great Flood of 1851 causes extensive damage in the Midwest; the town of Des Moines is virtually destroyed.
• May 6 – John Gorrie of Apalachicola, Florida is granted Patent No. 8080 for a machine to make ice.
• May 15 – Alpha Delta Pi sorority, the first secret society for women, is founded at Wesleyan College in Macon, Georgia.
• May 29 – Sojourner Truth delivers the first version of her "Ain't I a Woman?" speech, at the Women's Rights Convention in Akron, Ohio.

July–September edit

• 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 3 – The filibustering Lopez Expedition departs New Orleans for Cuba.
• 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–December edit

• October 15 – The City of Winona, Minnesota is founded.
• 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.

Undated edit

• 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.
• Hope College is established in Holland, Michigan, as the Pioneer School by Dutch immigrants.

Ongoing edit

• California Gold Rush (1848–1855)

• January 17 – A. B. Frost, illustrator (died 1928)
• January 19 – David Starr Jordan, ichthyologist, educator, eugenicist and peace activist (died 1924)
• January 24 – Marcus A. Smith, U.S. Senator from Arizona from 1912 to 1921 (died 1924)
• February 2 – Ella Giles Ruddy, author and essayist (died 1917)
• February 9 – Nora Trueblood Gause, humanitarian (died 1955)
• February 13 – Joseph B. Murdock, U.S. Navy admiral and New Hampshire politician (died 1931)
• March 14 – John Sebastian Little, politician, congressman (died 1916)
• March 19 – William Henry Stark, business leader (died 1936)
• March 26 – John Eisenmann, Cleveland architect (died 1924)
• April 13
  • Robert Abbe, surgeon (died 1928)
  • Helen M. Winslow, editor, author and publisher (died 1938)
• May 14 – Anna Laurens Dawes, author and suffragist (died 1938)
• May 15 – Lillian Resler Keister Harford, church organizer and editor (died 1935)
• 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)
• June 24 – Stuyvesant Fish, entrepreneur (died 1923)
• August 12 – Frank O. Briggs, U.S. Senator from New Jersey from 1907 to 1913 (died 1913)
• August 14 – Doc Holliday, born John H. Holliday, gunfighter, gambler and dentist (died 1887)
• September 7 – David King Udall, politician (died 1938)
• September 13 – Walter Reed, army physician, bacteriologist (died 1902)^[1]
• September 21 – Fanny Searls (died 1939), doctor and botanist.^[2]
• October 5 – Thomas Pollock Anshutz, painter and educator (died 1912)
• October 13 – Charles Sprague Pearce, painter (died 1914)
• October 20 – George Gandy, entrepreneur (died 1946)
• November 16
  • Minnie Hauk, operatic soprano (died 1929)
  • William Elbridge Sewell, naval officer and Governor of Guam (died 1904)
• 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)
• December 30 – Asa Griggs Candler, businessman and politician (died 1929)
• Albery Allson Whitman, African American poet (died 1901)

• January 17 – Thomas Lincoln, farmer and father of 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)
• March 11 – George McDuffie, 55th Governor of South Carolina from 1842 to 1846 (born 1790)
• 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)
• June 21 – Martin Chester Deming, American businessman and politician (b. 1789)^[3]
• 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)

• Timeline of United States history (1820–1859)

•   Media related to 1851 in the United States at Wikimedia Commons