The War of 1812 between Great Britain and the United States almost didn't happen.
The War of 1812 was fought between the United States and Great Britain backed by their Canadian colonies and Native American allies. Only 29 years after the American War for Independence, Great Britain, and the United States again found themselves embroiled in conflict. However, this war almost didn't happen.
Article I, Section Eight of the U.S. Constitution gives Congress the sole power to declare war, and it was the first time the legislative body had exercised that power. But it was an extremely close vote: Madison's party, the Democratic-Republicans, was divided over the prospect of starting a war with a global superpower like Great Britain. Across the aisle, the rival Federalist party was uniformly against the idea.
Federalists dominated New England, whose seafaring communities depended on trade with the British. So when the Madison-backed war resolution came up for a vote in Congress, not a single Federalist supported it. The measure passed anyway: On June 4, the House of Representatives voted 79 to 49 in favor of going to war. The Senate responded in kind on June 17, with 19 yes votes and 13 nos. No other declared war in U.S. history has ever been approved by such a narrow margin in Congress.
Despite all, the War of 1812 still happened when Madison signed the declaration on June 18, 1812, officially initiating the war. The war spanned two years and eight months, ending in February of 1815
