<P> American expansion into the Northwest (Ohio, Indiana, Michigan, Illinois and Wisconsin) was impeded by Indian raids . Some historians maintain that an American goal in the war was annex some or all of Canada, a view that many Canadians still share, while others argue that inducing the fear of such a seizure had merely been a U.S. tactic designed to obtain a bargaining chip . Some members of the British Parliament at the time and dissident American politicians such as John Randolph of Roanoke claimed that land hunger rather than maritime disputes was the main motivation for the American declaration . However, some historians, both Canadian and American, retain the view that desire to annex all or part of Canada was an American goal . 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 1814 at the peace conference, but lost battles that would have validated their claims . </P> <P> The war was fought in four theatres: on the oceans, where the warships and privateers of both sides preyed on each other's merchant shipping; along the Atlantic coast of the U.S., which was blockaded with increasing severity by the British, who also mounted large - scale raids in the later stages of the war; on the long frontier, running along the Great Lakes and Saint Lawrence River, which separated the U.S. from Upper and Lower Canada (Ontario and Quebec); and finally along the coast of the Gulf of Mexico . During the course of the war, both the Americans and British launched invasions of each other's territory, all 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 these occupied territories were restored at the end of the war . </P> <P> In the United States, battles such as New Orleans and the earlier successful defence of Baltimore (which inspired the lyrics of the U.S. national anthem, The Star - Spangled Banner) produced a sense of euphoria over a "second war of independence" against Britain . It ushered in an "Era of Good Feelings," in which the partisan animosity that had once verged on treason practically vanished . Canada also emerged from the war with a heightened sense of national feeling and solidarity . Britain, which had regarded the war as a sideshow to the Napoleonic Wars raging in Europe, was less affected by the fighting; its government and people subsequently welcomed an era of peaceful relations with the United States . </P> <P> The British were engaged in a life - and - death war with Napoleon and could not allow the Americans to help the enemy, regardless of their lawful neutral rights to do so . As Horsman explains, "If possible, England wished to avoid war with America, but not to the extent of allowing her to hinder the British war effort against France . Moreover...a large section of influential British opinion, both in the government and in the country, thought that America presented a threat to British maritime supremacy ." </P>

What were the causes of the war in 1812