- May 3 The May Uprising in Dresden begins - the last of the German revolutions of 1848
- May 10 Astor Place Riot: Backers of American actor and working class hero Edwin Forrest attempt to disrupt British actor William McReady's performance at Astor Place Opera House in NYC; Military troops supporting police shoot at the crowd, killing between 22 and 31 [1]
- May 15 Philadelphia Turngemeinde founded
- May 17 Fire destroy Centrum in St Louis, Missouri
Lincoln's Patent
May 22 Abraham Lincoln receives a patent (only US President to do so) for a device to lift a boat over shoals and obstructions
Opening of Euston Station
May 27 Opening of the Great Hall at Euston station in London
- May 28 Princess Marianne of the Netherlands and Albrecht of Prussia separate
- May 29 Lincoln says "You can fool some of the people all of the time, and all of the people some of the time, but you can not fool all of the people all of the time."
- May 31 Last edition of Orange sheet "Journal de La Haye"
Authors
Dictators
Explorers
Outlaws
Queens
Spies