>>4906490
quick summary:
Events
January 4 – The United States House of Representatives votes to stop sharing the Oregon Territory with the United Kingdom.
January 30 – The City of Milwaukee is incorporated in Wisconsin, merging Juneautown, Kilbourntown and Walker's Point following the Milwaukee Bridge War of 1845. Solomon Juneau is elected first mayor.
February 11 – Many Mormons begin their migration west from Nauvoo, Illinois to the Great Salt Lake, led by Brigham Young.
February 18 – In Austin, Texas, the newly formed Texas state government is officially installed.
February 27 – The Liberty Bell is cracked while being rung for George Washington's birthday.
April 26 – Mexican–American War: Open conflict begins over border disputes of Texas' boundaries.
May 9 – Mexican–American War – Battle of Palo Alto: Zachary Taylor defeats a Mexican force north of the Rio Grande at Palo Alto, Texas in the first major battle of the war.
May 14 – Mexican–American War: The United States declares war on Mexico.
May 23 – The Associated Press is founded in New York City.
September 21–24: Battle of Monterrey (Mexican–American War).
June 19 – Mexican–American War: The California Republic declares independence from Mexico.
June 15 – Bear Flag Revolt: American settlers in Sonoma, California start a rebellion against Mexico and proclaim the California Republic.
June 16 – The Oregon Treaty establishes the 49th parallel as the border between the United States and Canada, from the Rocky Mountains to the Strait of Juan de Fuca.
June 20 – The first officially recorded baseball game using modern rules developed by Alexander Cartwright is played in Hoboken, New Jersey.
July 8 – Battle of Monterey: Acting on instructions from Washington, D.C., Commodore John Drake Sloat orders his troops to occupy Monterey and Yerba Buena thus beginning the United States annexation of California.
August 11 – Establishment of the Smithsonian Institution in Washington, D.C..
November 31 – The Donner Party becomes snowbound.
December 29 – Iowa is admitted as the 29th U.S. state (see History of Iowa).
Undated
The portion of the District of Columbia that was ceded by Virginia in 1789 is re-ceded to it.
Elias Howe patents the sewing machine.
Stevens Linen Works business established in Dudley, Massachusetts.
Grinnell College, then called Iou University, is founded in Grinnell, Iowa Territory.
Ongoing
Mexican–American War (1846–1848)