I believe you meant the War of 1812, not 1912, as the only 1912 war I know is the Balkan Wars.
The War of 1812 was between the United Kingdom and the United States, as Britain didn't want the United States to expand westward along with capturing American troops and forcing them to join the British army. The war really ended with no borders being moved and nobody gained any land. The War of 1812 did bring long peace between the states and the British, known as the "era of good feelings".
