JTF2
My point is that Canada is not really viewed as a foreign country by most Americans. A lot of Americans believe it is not even necessary to have a passport to go to Canada, and I have seen this attitude manifested at the border with my own two eyes. Also note that we share professional sports leagues with Canada (NBA, MLB, NHL). Only the NFL does not have a Canadian franchise.
England and Australia are also perceived as different in part because they speak English much differently than Americans and Anglo-Canadians. People tend to be intrigued by English and Aussie accents but not by Anglo Canadian accents which sound more like our own speech. They are legit foreigners - they have different cultures and traditions, at least moreso than the differences we have with Canadians.