A young America stood up for herself and didn't back down from England (ended 3 years later by treaty).
The war banded together a nation (America) that was somewhat unpatiriotic and not militarily strong.
Mostly, it was a statement by America that we were now a strong, united front and in the future would be recognized as such.
Produced two future presidents and our national anthem (initially titled, 'The Defence of Ft. McHenry').