| January 2 | 1st photo of the Moon (French photographer Louis Daguerre) |
| January 6 | 2 day storm off Irish and English coast immortalized as "Big Wind" |
| January 9 | Daguerrotype photo process announced at French Academy of Science |
| January 9 | Thomas Henderson measures 1st stellar parallax (Alpha Centauri) |
| January 10 | Tea from India 1st arrives in UK |
| January 11 | Earthquake at Martinique destroys half of Port Royal-700 die |
| January 12 | Anthracite coal 1st used to smelt iron, Mauch Chunk, Penn |
| January 19 | Aden conquered by British East India Company |
| January 24 | Charles Darwin elected member of Royal Society |
| January 29 | Charles Darwin marries Emma Wedgwood |
| February 7 | Henry Clay declares in Senate "I had rather be right than president" |
| February 12 | Aroostock War: Boundary dispute between Maine and New Brunswick |
| February 18 | Detroit Boat Club forms (& still exists) |
| February 20 | Congress prohibits dueling in District of Columbia |
| February 24 | Steam shovel patented by William Otis, Philadelphia |
| February 25 | Seminoles and black allies shipped from Tampa Bay Florida, to West |
| February 26 | Jem Mason on Lottery wins 1st Grand National Steeplechase (Britain) |
| March 9 | Prussian government limits work week for children to 51 hours |
| March 23 | 1st known use of term OK (Boston) |
| March 23 | 1st recorded use of "OK" [oll korrect] (Boston's Morning Post) |
| March 26 | 1st Henley Royal Regatta |
| April 17 | Guatemala forms republic |
| April 19 | Treaty of London constitutes Belgium an independent kingdom and Luxembourg a Grand Duchy |
| May 4 | The Cunard Steamship Company Ltd forms San Bonifacio |
| June 7 | Hawaiian Declaration of Rights is signed |
| June 12 | 1st baseball game played in America |
| June 14 | 1st Henley Regatta held |
| June 18 | Dutch prince Willem Alexander PFL weds niece Princess Sophia |
| July 1 | Abdul-Medjid succeeds Mahmud II as Sultan of Turkey |
| July 3 | 1st state normal school in U.S. opens, Lexington, Massachusetts, with 3 students |
| July 27 | Chartist riots break out in Birmingham England |
| July 30 | Slave rebels, take over slaver Amistad |
| August 19 | Details of Louis Daguerre's 1st practical photographic process are released in Paris |
| August 23 | British capture Hong Kong from China |
| September 2 | Salon of Varietes opens in Amsterdam |
| September 6 | Cherokee Nation forms |
| September 6 | Great fire in NY |
| September 9 | John Herschel takes 1st glass plate photograph |
| September 11 | 1st Canadian track and field meet held (Caer Howell Grounds) |
| September 20 | 1st railroad in Netherland opens (Amsterdam-Haarlem) |
| October 10 | British troops under General Charles Napier occupy Beirut |
| November 3 | 1st opium war - 2 British frigates engage several Chinese junks |
| November 3 | Palace of Gulhane Turkey, freedom of religion proclaimed |
| November 13 | 1st U.S. anti-slavery party, Liberty Party, convenes in NY |
| November 17 | Giuseppe Verdi's opera "Oberte Conti Di," premieres in Milan |
| November 27 | American Statistical Association organizes in Boston |
| December 18 | 1st celestial photograph (of Moon) made in U.S., John Draper, New York City |
