The immediate stated causes for the U.S. declaration of war were a series of trade restrictions introduced by Britain to impede neutral trade with France with which Britain was also at war, that the U.S. contested as illegal under international law[4] and the impressment (forced recruitment) of U.S. citizens into the Royal Navy. An American rallying cry early in the war was "Free Trade and Sailors' Rights". Another major cause of American anger was alleged British military support for American Indians who were offering armed resistance to the United States.
The war was fought on the oceans, where the warships and privateers of both sides preyed on each other's merchant shipping, the American coast, which was blockaded to varying degrees of severity by the British who also mounted raids by troops in increasing strength, and the long frontier between the United States and Upper Canada (the present-day province of Ontario) and Lower Canada (the present-day province of Quebec), which ran along the Saint Lawrence River and the Great Lakes. The United States could directly attack British territory and armies only in this last theatre. During the course of the war, both the Americans and British launched invasions of each other's territory across this frontier, most of which were unsuccessful or gained only temporary success. At the end of the war, the British held parts of Maine and some outposts in the sparsely-populated west while the Americans held Canadian territory near Detroit, but all occupied territories were restored at the end of the war.
During the war, the Americans gained one of their unstated goals, by breaking the confederation of Native American tribes who were resisting American expansion westward. Their leader Tecumseh died in the Battle of the Thames, and several tribes were cut off from British support and signed treaties with the United States. While Natives continued to fight alongside British troops, they subsequently did so only as individual tribes or groups of warriors and where they received direct payment in the form of arms, gifts and rations.
