What was the War of 1812, how was it caused, and what happened in it?

The War of 1812 started due to the British navy taking American sailors for its own merchant marine, a policy known as impressment. At the time, Britain was fighting the Napoleonic Wars and needed every able body it could get for its merchant fleet. British ships stopped American ships in the process of trading with France and often took some American sailors, which the British claimed were deserters from its own navy. The British also did not vacate the forts of the Old Northwest Territory (the region around the Great Lakes), violating the deal of the Treaty of Paris of 1783, and Americans claimed the British there incited the Native Americans there to violence. While this is partially true, as tribes such as the Shawnee looked to the British for supplies, the natives were threatened by white encroachment on their land and acted accordingly. A group of young men in Congress known as War Hawks (Henry Clay and John Calhoun among the most famous of them) would also agitate for America to annex British Canada. Congress declared war in June 1812. The war went horribly for Americans. American attempts at taking Canada were repulsed by Canadians, but the Americans burned York. In retaliation, British forces burned the Executive Mansion in 1814. Americans did gain some heroes from this war, however. William Henry Harrison fought the British-backed Tecumseh at the Battle of Fallen Timbers and Tippecanoe, launching Harrison's political career and leading to the nation's shortest presidency to date. Oliver Hazard Perry defeated British frigates on the Great Lakes, leading the British to exit the Northwest Territory permanently. Finally, Andrew Jackson won the Battle of New Orleans in early 1815. Ironically, though, this battle was not necessary. By 1815, the British had quit fighting the French due to the capture and exile of Napoleon. British and American diplomats met in Ghent, Belgium in late 1814 and negotiated a peace treaty, thus ending the war. No property changed hands, and the peace treaty's only purpose was to end the war. Without modern communication devices, Jackson and his opposite British general Pakenham did not know about the peace treaty signed weeks before, and fought anyway.  

The end of the war brought about a strong sense of nationalism in America, as the nation had survived a war with the world's greatest superpower twice. The war was quite unpopular, especially in the Northeast, as they called it "Mr. Madison's War." There was a Federalist movement to get the Northeastern United States to secede from America, but after the war, it, along with the Federalist party, was discredited.