I don't disagree with most of the above posts in general, but border disputes between the US and Canada continued until almost mid-century (that's why Polk's campaign slogan was "54-40 or fight!,") and most historians would ascribe the end of impressment to the end of the Napoleonic Wars rather than an American "victory" in the War of 1812. It is true, however, that the defeat of Tecumseh and the collapse of subsequent attempts at forming Indian confederacies marked more or less the end of British meddling on the frontier. Ultimately, the gains made during the war had to do, as some have pointed out, with national identity.
I have to agree with the above posters. While the deaths which result from wars are always a negative outcome of war, positives can usually be found. America came to have an identity apart from Britain (according to Britain)--a good thing for Americans, bad thing for the British.
The United States of America declared itself so in 1776. In 1783 Britain formally recognized the sovereignty of the United States, but for years chose to ignore many statutes of the treaty. Between 1783 and 1812 the new nation was just that, a new nation, weak, economically unstable, and trying to create a political reality from the ideological principles of the enlightenment. In addition, the subsequent economic treaties between the U.S. and European nations were of little success. Clearly the U.S. was not in the best position, economically or politically for war. However although the war ended in a draw, the War of 1812 (usually referred to as the 2nd war for American Independence) was absolutely worthwhile for the U.S. for the following reasons:
1. British impressment of American ships ended
2. American ships were no longer pawns between British and French struggles on the high seas
3. The Mississippi River at the Gulf of Mexico was the jurisdiction of the U.S.
4. Political relations between the U.S. and Britain finally began to improve which ultimately improved their economic relations
The previous post is on target. The U. S. once and for all ridded itself of any threat of Great Britain making claims against our lands. We maintained our territorial integrity and Britain was forced to be happy with their Canadian lands. The U. S. also gained greater respect from England, and we have become the greatest of allies ever since, with England now owing us their undying support after coming to their rescue during the two world wars.
Of course, there is no way to answer this question in an objective way. All we can say objectively is that the US did gain something very important from this war. What it gained was true independence from Great Britian. Before the war, the British had in many ways treated the US as if it were still a British possession. They impressed US sailors and kept forts on US territory. After the war, this all changed. From many people's perspectives, this made the war worthwhile. However, that is a value judgement and not an objective fact.