The origins of the War of 1812 (1812-1815), between the United States and the British Empire and its First Nation allies, have been long debated. There were multiple factors that caused the US declaration of war on Britain:

1. A series of trade restrictions introduced by Britain to impede American trade with France with which Britain was at war (the US contested the restrictions as illegal under international law).^[26]
2. The impressment (forced recruitment) of seamen on US vessels into the Royal Navy (the British claimed that they were British deserters).^[27]
3. The British military support for American Indians who were offering armed resistance to the expansion of the American frontier to the Northwest Territory.^[28]
4. A possible desire by the US to annex some or all of Canada. Implicit but powerful was a US motivation and desire to uphold national honor in the face of what they considered to be British insults, such as the Chesapeake affair.^[29]