The United States took the initiative in declaring war for multiple reasons. In 1807, Britain introduced a series of trade restrictions to impede ongoing American trade with France, Britain's longtime rival. The U.S. contested these restrictions as illegal under international law. Both the impressment of American citizens into the Royal Navy, and Britain's military support of American Indians who were attacking American settlers moving into the Northwest further aggravated tensions. Indian raids hindered the expansion of U.S. into potentially valuable farmlands in the Northwest Territory, comprising the modern states of Ohio, Indiana, Illinois, Michigan, and Wisconsin. Some British officials – and some dissident Americans – charged that the goal was to annex part of Canada, but they did not specify which part. The states nearest Canada strongly opposed the war.
Most important, the United States sought to uphold its national honor in the face of what they considered to be British insults, such as the Chesapeake affair. Although the British made some concessions before the war on neutral trade, they insisted on the right to reclaim their deserting sailors. The British also had the long-standing goal of creating a large "neutral" Indian state that would cover much of Ohio, Indiana and Michigan. They made the demand as late as the fall of 1814 at the peace conference, but lost control of western Ontario at key battles on Lake Erie, thus giving the Americans control of the proposed neutral zone