1850
Events
January–March
- January 29 - Henry Clay introduces the Compromise of 1850 to the United States Congress.
- January 31 - The University of Rochester is founded in Rochester, New York.
- January – Sacramento floods.
- February 1 - Abraham Lincoln’s second son, Edward Baker Lincoln, died at the age of three after 52 days for struggling with tuberculosis before his fourth birthday in Springfield, Illinois.
- February 28 - The University of Utah opens in Salt Lake City.
- March 5 - The Britannia Bridge opens over the Menai Strait in Wales.
- March 7 - United States Senator Daniel Webster gives his "Seventh of March" speech, in which he endorses the Compromise of 1850, in order to prevent a possible civil war.
- March 16 - Nathaniel Hawthorne's historical novel The Scarlet Letter is published in Boston, Massachusetts.
- March 19 - American Express is founded by Henry Wells and William Fargo.
- March 31 - The paddle steamer, bound from Cork to London, is wrecked in the English Channel with the loss of all 250 on board.
April–June
- April 4 - Los Angeles is incorporated as a city in California.
- April 15
- * San Francisco is incorporated as a city in California.
- * Angers Bridge collapses in France killing around 226 of the soldiers crossing it at the time.
- April 19 - The Clayton–Bulwer Treaty is signed by the United States and Great Britain, allowing both countries to share Nicaragua, and not claim complete control over the proposed Nicaragua Canal.
- April
- * Pope Pius IX returns from exile to Rome.
- * Stephen Foster's parlor ballad "Ah! May the Red Rose Live Alway" is published in the United States.
- May 15 - The Bloody Island Massacre takes place at Clear Lake in northern California.
- May 23 - The puts to sea from New York to search for Franklin's lost expedition in the Arctic.
- May 25 - The hippopotamus Obaysch arrives at London Zoo from Egypt, the first seen in Europe since Roman times.
- June 1
- * The transportation of British convicts to Western Australia begins, as the transportation of British convicts to other parts of Australia is phased out, when the ship Scindian arrives in Fremantle, with 75 male prisoners.
- * The postage stamp issues of Austria begin with a series of imperforate typographed stamps, featuring the coat of arms.
- * The 1850 United States census shows that 11.2% of the population classed as "Negro" are of mixed race.
- June 3 - Kansas City, Missouri, is incorporated by Jackson County, Missouri, as the Town of Kansas.
- June 3 - the Cayuse Five were executed for murder following the Whitman massacre
July–September
- July - Taiping Rebellion: Hong Xiuquan orders the general mobilisation of rebel forces in China.
- July 1 - St. Mary School for Boys opens its doors in Dayton, Ohio.
- July 2 - Twice-served former British Prime Minister Sir Robert Peel dies following a fall from his horse at Constitution Hill, London.
- July 9
- * The Báb is executed by a firing squad in Tabriz, Persia, for claiming to be a prophet.
- * Vice President Millard Fillmore becomes the 13th president of the United States upon the death of President Zachary Taylor, aged 65.
- July 17 – Vega becomes the first star to be photographed.
- July 19 - The ship Elizabeth, an American merchant freighter carrying cargo that included mostly marble from Carrara, slammed into a sandbar less than 100 yards from Fire Island, New York, drowning Margaret Fuller, her husband Ossoli, and their young son Angelino.
- August 28 - Richard Wagner's romantic opera Lohengrin premieres under the direction of Franz Liszt, in Weimar.
- September 4 - The Eusébio de Queirós Law is passed in the Brazilian Empire to abolish the international slave trade.
- September 9
- * California is admitted as the 31st U.S. state.
- * The New Mexico Territory is organized by order of the United States Congress.
- September 12 – The 1850 Xichang earthquake shakes the Chinese province of Sichuan killing more than 20,000 people.
- September 13 - Piz Bernina, the highest summit of the eastern Alps, is first ascended.
- September 18
- * The Fugitive Slave Law is passed by the United States Congress.
- * Harriet Tubman becomes an official conductor of the Underground Railroad.
- September 29 - Papal bull Universalis Ecclesiae: The Catholic hierarchy is re-established in England and Wales, by Pope Pius IX and future Pope Pius X.
October–December
- October 1 - The University of Sydney is founded.
- October 19 - The Phi Kappa Sigma international fraternity is founded, at the University of Pennsylvania.
- October 28 - Delegate Edward Ralph May delivers a speech on behalf of African-American suffrage, to the Indiana Constitutional Convention.
- November
- * Taiping Rebellion: The first clashes of the Taiping Rebellion occur, between the Imperialist militia and the Heavenly Army.
- * Undergraduates at Exeter College, Oxford arrange a "foot grind", the first organised university athletic event.
- November 29 - The treaty known as the Punctation of Olmütz is signed in Olomouc. It means diplomatic capitulation of Prussia to the Austrian Empire, which takes over the leadership of the German Confederation.
- December 16 - Members of the Canterbury Association, the first settlers bound for Christchurch, arrive from England at the port of Lyttelton, New Zealand, aboard the Charlotte Jane and Randolph.
Date unknown
- Dost Mohammad Barakzai, emir of Afghanistan, captures Balkh.
- The first portion of the Oudh Bequest is transferred from Oudh State in the British Raj to the Shia Islam holy cities of Najaf and Karbala, in Persia.
- The American system of watch manufacturing is started in Roxbury, Massachusetts, by the Waltham Watch Company.
- Bingley Hall, the world's first purpose-built exhibition hall, opens in Birmingham, England.
- Allan Pinkerton forms the North-Western Police Agency, later the Pinkerton National Detective Agency, in the United States.
- The temperance organisation, International Organisation of Good Templars, is established in Utica, New York, as the order of the Knights of Jericho.
- Mayer Lehman arrives from Germany to join his siblings in Lehman Brothers dry-goods business in Montgomery, Alabama.
- One of the original segments of the historic Pacific Highway in Washington in Clark and Cowlitz counties is established.
- German physicist Rudolf Clausius publishes his paper on the mechanical theory of heat which first states the basic ideas of the second law of thermodynamics.
- The city of Manchester, England, reaches 400,000 inhabitants.
- From this year until 1880, 144,000 East Indian laborers go to Trinidad and 39,000 to Jamaica.
- Ongoing - Great Famine subsides.
Births
January–February
- January 1 - John Barclay Armstrong, Texas Ranger, U.S. Marshal
- January 6
- * Eduard Bernstein, German social democratic theoretician, politician
- * Xaver Scharwenka, Polish-German composer
- January 10 - John Wellborn Root, American architect
- January 11 - Philipp von Ferrary, Italian stamp collector
- January 14 - Pierre Loti, French novelist
- January 15
- * Mihai Eminescu, Romanian romantic poet
- * Sofia Kovalevskaya, Russian mathematician
- January 18 - Seth Low, American educator
- January 19 - Augustine Birrell, English author, politician
- January 24 - Hermann Ebbinghaus, German psychologist
- January 27
- * John Collier, British writer and painter
- * Edward Smith, British captain of the Titanic
- * Samuel Gompers, American labor union leader
- January 29
- * Sir Ebenezer Howard, British urban planner
- * Lawrence Hargrave, Australian engineer
- January 30 - Victor-Constant Michel, French general
- February 8 - Kate Chopin, American writer
- February 10 - Alexander von Linsingen, German general
- February 12 - William Morris Davis, American geographer
- February 14 - Kiyoura Keigo, Prime Minister of Japan
- February 15 - Albert B. Cummins, American lawyer and politician
- February 17 - Alf Morgans, 4th Premier of Western Australia
- February 18 - Sir George Henschel, English musician
- February 23 - César Ritz, Swiss hotelier
- February 27 - Henry E. Huntington, American railroad pioneer, art collector
March–April
- March 6 - Sagen Ishizuka, Japanese physician, dietitian
- March 7
- * Tomáš Garrigue Masaryk, President of Czechoslovakia
- * Champ Clark, American politician
- March 9
- * Josias von Heeringen, German general
- * Sir Hamo Thornycroft, British sculptor
- March 10 - Spencer Gore, British tennis player, cricketer
- March 13 - Sir Hugh John Macdonald, premier of Manitoba
- March 26 - Edward Bellamy, American author
- March 31 - Charles Doolittle Walcott, American invertebrate paleontologist
- April 1 - Hans von Pechmann, German chemist
- April 8 - Kawamura Kageaki, Japanese field marshal
- April 9 - Sir Julius Wernher, German-born British businessman, art collector
- April 10
- * Fanny Davenport, English-born American actress
- * Mary Emilie Holmes, American geologist, educator
- April 12 - Nikolai Golitsyn, Prime Minister of Russia
- April 13 - Arthur Matthew Weld Downing, British astronomer
- April 15
- * Edmund Peck, Canadian missionary
- * William Thomas Pipes, Canadian politician, 6th Premier of Nova Scotia
- April 18 - Jo Labadie, American labor organizer
- April 20 - Daniel Chester French, American sculptor
- April 23 - Agda Montelius, Swedish feminist
- April 26
- * Harry Bates, English sculptor
- * James Drake, Australian politician
- April 27 - Hans Hartwig von Beseler, German general