It was a whole lot about impressment. British ships would impress (force) American sailors into working on their ships under the guise of catching people who had escaped their service on English ships. America was none too happy about this, and asked the British to stop. They refused. America proceeded to invade Canada (which was at the time English territory) in order to attempt force the English to knock it off. America proceeded to get its ass kicked up and down the Eastern seaboard, culminating in English troops burning down the White House (burn marks from this are still visible on the Eastern Portico). Fortunately for America, England had other concerns (like, as always, the French) to deal with, and signed a peace treaty which ended the war and stopped impressment.
A few days later, Andrew Jackson won one of the few American victories in the war, which went a long way to securing America's role as a military power. The fact that America's military was able to beat the English military in a single stand up battle was impressive at the time.
So, from the American perspective, it was about a righteous struggle against people being shanghaied into military service for a foreign country. I dunno about other groups, though. I've read a bunch of different accounts though, from both American and foreign sources, and this seems pretty consistent
