<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> <P> The British had two goals: All parties were committed to the defeat of France, and this required sailors (hence the need for impressment), and it required all - out commercial war against France (hence the restrictions imposed on American merchant ships). On the question of trade with America the British parties split . As Horsman argues, "Some restrictions on neutral commerce were essential for England in this period . That this restriction took such an extreme form after 1807 stemmed not only from the effort to defeat Napoleon, but also from the undoubted jealousy of America's commercial prosperity that existed in England . America was unfortunate in that for most of the period from 1803 to 1812 political power in England was held by a group that was pledged not only to the defeat of France, but also to a rigid maintenance of Britain's commercial supremacy ." That group was weakened by Whigs friendly to the U.S. in mid-1812 and the policies were reversed, but too late for the U.S. had already declared war . By 1815 Britain was no longer controlled by politicians dedicated to commercial supremacy, so that cause had vanished . </P> <P> The British were hindered by weak diplomats in Washington (such as David Erskine) who misrepresented British policy and by communications that were so slow the Americans did not learn of the reversal of policy until they had declared war . </P>

One of the major reasons for american entry in the war of 1812 was the