The War of 1812 was a military conflict fought between the forces of the United States of America and those of the British Empire. The Americans declared war in 1812 for several reasons, including trade restrictions due to Britain's ongoing war with France, the impressment of American merchant sailors into the Royal Navy, British support of American Indian tribes against American expansion, outrage over insults to national honour after humiliations on the high seas and possible American desire to annex Canada.
Tied down in Europe until 1814, the British at first used defensive strategy, repelling multiple American invasions of the provinces of Upper and Lower Canada. However, the Americans gained control over Lake Erie in 1813, seized parts of western Ontario, and ended the prospect of an Indian confederacy and an independent Indian state in the Midwest under British sponsorship. In the Southwest, General Andrew Jackson destroyed the military strength of the Creek nation at the Battle of Horseshoe Bend in 1814. With the defeat of Napoleon in 1814, the British adopted a more aggressive strategy, sending in three large invasion armies. The British victory at the Battle of Bladensburg in August 1814 allowed them to capture and burn Washington, D.C. American victories in September 1814 and January 1815 repulsed all three British invasions in New York, Baltimore and New Orleans.
The war was fought in three theatres. At sea, warships and privateers of both sides attacked each other's merchant ships. The British blockaded the Atlantic coast of the U.S. and mounted large-scale raids in the later stages of the war. American successes at sea were characterized by single ship duels against British frigates, and combat against British provincial vessels on the Great Lakes, such as at the action on Lake Erie. Both land and naval battles were fought on the frontier, which ran along the Great Lakes and Saint Lawrence River. The South and the Gulf coast saw major land battles in which the American forces destroyed Britain's Indian allies and repulsed the main British invasion force at New Orleans. Both sides invaded each other's territory, but these invasions were unsuccessful or temporary. At the end of the war, both sides occupied parts of the other's territory, but these areas were restored by the Treaty of Ghent.
In the United States, battles such as the Battle of New Orleans of 1815 and the Battle of Baltimore of 1814 (which inspired the lyrics of the United States national anthem, "The Star-Spangle Banner") produced a sense of euphoria over a "second war of independence" against Britain. It ushered in an "Era of Good Feelings" in which partisan animosity nearly vanished. Canada also emerged from the war with a heightened sense of national feeling and solidarity, having repelled multiple American invasions. Battles such as the Battle of Queenston Heights and the Battle of Crysler's Farm were used as such examples by Canadians. The war is scarcely remembered in Britain today, as it regarded the war as a sideshow to the much larger war against Napoleon raging in Europe; as such it welcomed an era of peaceful relations and trade with the United States.