In the 1920s, we did. Here’s the map.
I see that Minnesota was key, launching a spearhead assault on Fortress Winnipeg. The stuff on the east side of the continent was all about blocking British aid, but there in the middle, look how Minnesotans would just plunge north, all the way up to Baffin Island, because of course we want a barren, rocky, snow-covered bit of tundra with hardly anybody living on it.
I hope someone in defense saw the light of reason, though. Everytime we try to invade Canada, we get our butts kicked. We must learn the lesson of the Revolutionary War, the War of 1812, Canadian Bacon, and South Park: Bigger, Longer, and Uncut.