What was the importance of the War of 1812 for the new nation of America?
The War of 1812 was important for two main reasons.
First, it is sometimes called the second war for American independence. This is because part of the cause of the war was Britain's unwillingness to respect the rights of the new country. The impressment of American sailors and the keeping of forts on US territory were examples of this. The war helped cause Britain to fully acknowledge American independence.
Second, the "win" in the war made Americans much more confident and nationalistic. They came to feel that theirs was an important country. Perhaps the most obvious manifestation of this was in the Monroe Doctrine that was announced about 10 years after the war. This showed that the US saw itself as a power in the world.