Who did America defeat during the war of 1812?

The British came off better due to the fact that they completed their objectives; defend Canada by fending off the Americans who tried to invade.

American Deaths:

2,260 killed in action.
4,505 wounded.
Approx. 17,000 died from disease (estimated).

British Deaths:

1,600 killed in action.
3,679 wounded.
3,321 died from disease.

The Americans having failed their objectives lately forfeited and wanted to sign a peace treaty.