| January 1 | Michigan is 1st state to abolish capital punishment |
| January 1 | Netherlands Haarlem's Current newspaper starts publishing |
| January 3 | California town of Yerba Buena renamed San Francisco |
| January 9 | 1st San Francisco newspaper published (California Star) |
| January 14 | Conspiracy in New Mexico against US |
| January 15 | 1st Swedish magazine in U.S., Skandinavia, published in New York City |
| January 24 | 1,500 New Mexican Indians and Mexicans defeated by U.S. Col Price |
| January 30 | Yerba Buena renamed San Francisco |
| February 4 | 1st U.S. telegraph co established in Maryland |
| February 22 | Battle of Buena Vista: U.S. troops beat Mexican army |
| February 23 | Battle of Buena Vista Mexico; Zachary Taylor defeats Mexicans |
| February 25 | State University of Iowa is approved |
| February 28 | U.S. defeats Mexico in battle of Sacramento |
| March 1 | Michigan becomes 1st English-speaking jurisdiction to abolish the death penalty (except for treason against the state) |
| March 3 | Post Office Department authorized to issue postage stamps |
| March 7 | U.S. General Scott occupies Vera Cruz Mexico |
| March 10 | 1st money minted in Hawaii |
| March 17 | "Macbeth" opera premieres in Florence |
| March 18 | 1st Dutch public telegram |
| March 25 | Pope Pius IX encyclical "On aid for Ireland" |
| April 14 | Persia and Osmaanse sign 2nd Treaty of Erzurum |
| April 28 | George B. Vashon becomes 1st black to enter New York State Bar |
| May 4 | New York State creates a Board of Commissioners of Emigration |
| May 5 | American Medical Association organized (Philadelphia) |
| May 7 | American Medical Association organizes in Philadelphia |
| May 8 | Robert Thompson patents rubber tire |
| May 31 | Rotterdam-Hague Railway opens |
| June 3 | Rotterdam-Hague Railway opens |
| June 10 | Chicago Tribune begins publishing |
| June 14 | Robert von Bunsen invents the Bunsen burner |
| June 22 | Doughnut created |
| June 27 | NY and Boston linked by telegraph wires |
| July 1 | 1st U.S. postage stamps go on sale, 5 cents Franklin and 10 cents Washington, New York City |
| July 2 | Envelope bearing 1st U.S. 10 cents stamps, still exists today |
| July 10 | Urbain J J Leverrier and John Couch Adams, codiscoverers of Neptune meet for 1st time at home of John Herschel |
| July 20 | German astronomer Theodor discovers Comet Brorsen-Metcalf |
| July 24 | Brigham Young and his Mormon followers arrive at Salt Lake City, Utah |
| July 24 | Rotary-type printing press patents by Richard March Hoe, New York City |
| July 26 | Liberia declares independence from American Colonization Society |
| July 26 | Moses Garrish Farmer builds 1st miniature train for children to ride |
| August 24 | Charlotte Bronte finishes manuscript of "Jane Eyre" |
| September 8 | U.S. under General Scott defeat Mexicans at Battle of Molino del Rey |
| September 10 | 1st theater opens in Hawaii |
| September 11 | 1st singing of Stephen Fosters "Susanna" (in Pittsburgh) |
| September 13 | American-Mexican war: U.S. General Winfield Scott captures Mexico City |
| September 14 | U.S. Marines under General Scott enter Mexico City (halls of Montezuma) |
| September 16 | United Shakespeare Company buys his home in Stratford-upon-Avon |
| October 1 | Maria Mitchell discovers a non-naked-eye comet |
| October 16 | Charlotte Bronte's book "Jane Eyre" published |
| October 20 | Little William Nelman poisons his grandpa |
| November 21 | Steamer "Phoenix" is lost on Lake Michigan, kills 200 |
| November 25 | Opera "Marta" is produced (Vienna) |
| November 26 | Alfred de Mussets "Un Caprice," premieres in Paris |
| November 28 | Bologna: church San Francisco dei Minori Conventuali initiated with premier of Rossini's Tantum ergo |
| November 29 | Indians kill Marcus and Narcissa Whitman, 11 settle in Walla Walla Ore |
| December 3 | Frederick Douglass publishes 1st issue of his newspaper "North Star" |
BrainyHistory
