It is important to honor all people who sacrificed to allow the United States to exist and to grow. That is one reason to honor the heroes of this war even though it happened so long ago.
It is also important that we think about the importance of the War of 1812. We often overlook this war because it was short, had relatively few battles, and did not end in the taking of any land. However, it can be thought of as a second war for independence.
Had the US not fought Great Britain to a draw in this war, it is hard to know what the country's future would have looked like. Up until the war, the British were not really treating the US like a truly sovereign country. Instead, they were taking actions, like impressing American sailors, that made it seem as if they still saw the US as a British colony. If they had been able to keep on doing that and to keep on doing things like having forts in US territory from which they stirred up Indian attacks on American settlers, US history might have been very different.
Therefore, the people who fought in the War of 1812 should be honored both because they fought for the country and because the war in which they fought was important for the US's independence.