From PoliticalProf answers:
you’re off the hook: no Americans consider Canadians to be Americans.
—update: besides, your population density per square mile is in the single digits … ;-)
A little more analysis: I think Politicalprof handled this well. Here’s my contribution: many Americans think it’s acceptable to refer to the USA as America, and that’s fine - in the USA. When you travel abroad, or live abroad as I or hnhobu do, it becomes incredibly ignorant and offensive to other Americans, be they North, Central, or South.
Two further contributions from the UK: Here, people hear an American accent and ask, ‘Are you Canadian?’ Two reasons: 1) they don’t want to offend the Canadians by presuming they are from the USA with the similar accent, and 2) they recognise being ‘American’ means more than being from the USA, and they are clever so they like to make their knowledge public :-).
The simple fact is, internationally, it is disrespectful (and factually inaccurate) to call the country of the USA, ‘America’; because Latin Americans were using ‘America’ to reference their collective countries LONG before it became popular in the USA. It’s also disrespectful to assume all Americans come (only) from the USA. Domestically, in the USA, the terms of usage have a common cultural meaning to denote one country; that’s fine, if you’re speaking exclusively to other people from the USA when using these terms.
Don’t believe me? … come have a few beers with some of the ‘Americans’ in Britain. Those South Americans can get pretty testy about it… :-)