30 Apr 1812
State of Louisiana formed out of Orleans Territory and Louisiana Territory renamed to Missouri Territory.
11 May 1812London, England
British Prime Minister Spencer Perceval assassinated by a maverick for personal grievances.
01 Jun 1812
President Madison recommends war with Britain. Sailor impressment, British support of Indian tribes in the west, and refusal to rescind the Orders-in-Council are cited as justifications.
01 Jun 1812Baltimore, US
Baltimore citizens riot against anti-war Federalists. Ends 1st September 1812.
04 Jun 1812
War bill passed by House of Representatives
18 Jun 1812
President Madison signs US Declaration of War against Great Britain.
23 Jun 1812North Atlantic
USS President pursues HMS Belvidera, which escapes with news to Halifax that war is declared.
23 Jun 1812
British government repeals the Orders-in-Council, sends immediate notice by ship to ambassador in Washington.