May 1848

Monday 01:

Phi Gamma Delta (Fiji), collegiate social fraternity, founded at Jefferson College (now Washington and Jefferson College) in Canonsburg, PA

Saturday 13:

First performance of Finland's national anthem.

Thursday 18:

Opening of the first German National Assembly (Nationalversammlung) in Frankfurt, Germany.

Friday 19:

Mexican-American War: Treaty of Guadalupe Hidalgo – Mexico ratifies the treaty thus ending the war and ceding California, Nevada, Utah and parts of five other modern-day U.S. states to the USA for USD $15 million.

Monday 29:

Wisconsin is admitted as the 30th U.S. state.