Births on October 3

James Jackson Putnam, American neurologist and academic (d. 1918)

James Jackson Putnam (October 3, 1846 – November 4, 1918) was an American neurologist.

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.