What is so important about the War of 1812?

The significance of the War of 1812 for the United States was that it was the fledgling nation's first major conflict since it had won its independence only a quarter century earlier. Great Britain may not have continued to rule its former colonies, but it certainly tried to exert influence and control over the United States through its dominant naval forces and economic might. The saying at the time was that the war was fought over "Free Trade and Sailors' Rights." Britain restricted trade between the US and Continental Europe through the Orders in Council, and it used impressment to force American sailors to join the British Navy. The US had to show that it was worthy of being considered an equal partner on the world stage and couldn't let Britain push it around. However, as the nation soon found, it really was up against a relatively great force, and the war ended on less than victorious terms, despite the US having won some of the battles. What did the US gain by fighting the War of 1812? A stronger sense of nationalism, an end to the Federalist Party, and the beginning of the expansionism that led a century later to a United States that stretched from Maine to California.
http://www.pbs.org/wned/war-of-1812/essays/american-perspective/

https://www.marinersmuseum.org/sites/micro/usnavy/08/08a.htm