1812 – War of 1812: The U.S. Congress declares war on the United Kingdom
. The War of 1812 was a 32-month military conflict between the United States and the British Empire and their Indian allies which resulted in no territorial change between the Empire and the US, but a resolution of many issues which remained from the American War of Independence. The United States declared war in 1812 for several reasons, including trade restrictions brought about by Britain's continuing 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 honor after humiliations on the high seas, and possible American interest in annexing Canada. The war was fought in three principal theatres. Firstly, at sea, warships and privateers of both sides attacked each other's merchant ships, while the British blockaded the Atlantic coast of the U.S. and mounted large-scale raids in the later stages of the war. Secondly, both land and naval battles were fought on the American–Canadian frontier, which ran along the Great Lakes, the Saint Lawrence River and the northern end of Lake Champlain. Thirdly, the American South and Gulf Coast also saw major land battles in which the American forces defeated Britain's Indian allies and repulsed a British invasion force at New Orleans. Both sides invaded each other's territory, but these invasions were unsuccessful or made temporary by the Treaty of Ghent, which restored all occupied territory to its pre-war owner.