February 2:
A.D. 962: German king Otto I is crowned Emperor.
A.D. 1536: Buenos Aires is founded.
A.D. 1848: The Treaty of Guadalupe Hidalgo ends the Mexican Wars. The U.S. acquires California, parts of Texas, New Mexico, and Arizona for $15 million (EDIT: and Nevada and Utah).
A.D. 1882: The Catholic men's organization, the Knights of Columbus, is formed.