Deaths on December 15

Jacques Charles François Sturm, French mathematician and academic (b. 1803)

Jacques Charles François Sturm (29 September 1803 – 15 December 1855) was a French mathematician.

14 Feb

Telegraphy
Texas is linked by telegraph to the rest of the United States, with the completion of a connection between New Orleans and Marshall, Texas.
22 Feb

State College, Pennsylvania
The Pennsylvania State University is founded in State College, Pennsylvania (as the Farmers' High School of Pennsylvania).
30 Mar

Border Ruffian
Origins of the American Civil War: "Border Ruffians" from Missouri invade Kansas and force election of a pro-slavery legislature.
1 Jun

William Walker (filibuster)
The American adventurer William Walker conquers Nicaragua.
4 Jul

Leaves of Grass
The first edition of Walt Whitman's book of poems, Leaves of Grass, is published In Brooklyn.