Their every attempt to invade and subjugate Canada during 1812-14 failed miserably, and our troops burned Washington. They did, however, do well on the Great Lakes in that war. All in all, I'd say they lost it, but only in the sense that their offensive aims were frustrated. They did not lose it decisively, but conditionally. They have forgotten this by focusing on a few isolated naval victories and the Battle of New Orleans, which they did win.

They won a war with Mexico and a war with Spain, and gained much territory...official or unofficial territory...out of both those endeavours, including Calfornia, Cuba (temporarily), the Phillipines, the Southwest USA, and Puerto Rico.

They lost the War in Vietnam...not on the battlefield, but on the larger field of politics and public opinion. The best evidence of that was their final, hurried departure by helicopter from the roof of their embassy in Saigon.

They managed a draw in Korea.

They won decisively in both World Wars.

And by the way, they killed me, but I still beat them. You can see my statue on the Canadian side of Niagara.