The War of 1812 didn't begin and end in the same year - 1812.

People usually get confused over the name of the war. "The war of 1812" makes many people think that the war began and ended in the same year. However, in reality, it lasted 32 months following the U.S. declaration of war on Britain in June 1812. That is actually longer than many other wars such as the Mexican-American War, Spanish-American War, and U.S. involvement in World War I.

Another confusing thing about the War of 1812 is the Battle of New Orleans, the largest of the war and a resounding U.S. victory. The battle occurred in January 1815—two weeks after U.S. and British envoys signed a peace treaty in Ghent, Belgium. News traveled slowly then. Even so, it’s technically incorrect to say that the Battle of New Orleans was fought after the war, which didn’t officially end until February 16, 1815, when the Senate and President James Madison ratified the peace treaty.

For roughly a century, the conflict didn’t merit so much as a capital W in its name and was often called “the war of 1812". The British were even more dismissive. They termed it “the American War of 1812,” to distinguish the conflict from the great Napoleonic War in progress at the same time.