Births on April 9

Paolo Tosti, Italian-English composer and educator (d. 1916)

Sir Francesco Paolo Tosti KCVO (9 April 1846, Ortona, Abruzzo – 2 December 1916, Rome) was an Italian composer and music teacher.

11 May

Mexican-American War
President James K. Polk asked for a Declaration of War against Mexico, starting the Mexican-American War. It is approved on May 13.
7 Jul

Conquest of California
American troops occupy Monterey and Yerba Buena, thus beginning the conquest of California.
10 Sep

Sewing machine
Elias Howe is granted a patent for the sewing machine.
24 Sep

Zachary Taylor
Mexican-American War: General Zachary Taylor captures Monterrey.
16 Oct

Ether Dome
William T. G. Morton first demonstrated ether anesthesia at the Massachusetts General Hospital in the Ether Dome.