Canadians care about (sometimes obsess about) national identity. Americans (as far as I can see) just have one, whether they like it or not.

Historically...
The part of Canada I live in (Ontario, on the border) was settled mainly by United Empire Loyalists during and after the American revolution. The rest of ontario was owned pretty outright by the Hudsons Bay Company and the Northwest Company. Quebec was a french colony that had been lost to Britain in the French-English hostilities and had reached a pretty good understanding with the governer of Upper Canada (got to keep their language, religion, etc.) I don't really know what was going on Eastwards, but no one seemed exactly motivated to throw off British rule. Especially after the War of 1812. Ocassionally a 'patriot' would pop up, like the local character Pirate Bill Johnston, and try to 'liberate' Canada, but it's hard to force independance on people who are happy without it.
:-)

So you fought for your country, and we negotiated for ours...but all in all, we're good neighbors. Hey, if it wasn't for your big scary army, we woulda never got together and formed a country. The fathers of our country found it a very persuasive argument when trying to convince those independant minded maritimers to join Confederation. So here we are!

History lesson over. :-)

Ceitagh