Most Americans are only dimly aware the rest of the world exists, but most Americans really aren't overly attached to the American state or all "huzzah!" over being American. If you call an American a Canadian, he'll laugh and maybe correct you; if you call a Brazilian Hispanic or a Pole Russian you risk starting World War 3.
In the original meaning of Canadian (Canadiens), it referred to the French inhabitants of Canada, namely French Quebecers (Acadians were French, but not French Canadian). If someone identified as Canadian, that implied they were French. This of course changed after the British Conquest of Canada.
In the early 1800's, the Maritime Provinces and Ontario were culturally and linguistically American, because a majority of the people living there were United Empire Loyalists who had fled the colonies after the American Revolution. I don't recall the exact percentage of loyalists in Canada overall, but I think shortly after the American revolution, some 80% of the people living in New Brunswick were loyalists (or descendants of loyalists) who had fled the colonies. Loyalists were also the majority in Upper Canada (Ontario), at nearly 75% of the population. By 1914, those percentages had fallen drastically, with United Empire Loyalists being a much lower percentage.
During the War of 1812, the two largest ethnic groups in Canada, were the French Canadians and British loyalists who had fled the Thirteen Colonies after the American revolution. When America tried to invade Canada during the War of 1812, many of the Canadians helping to repel the invasion, were exiled Americans who had remained loyal to the British Crown.
Conversely, at the same time all the British loyalists were fleeing the Colonies for Canada, French Canadians / Acadians were migrating south to the United States. The Acadians left Canada, because the British forcefully evicted them after the Seven Years war for refusing to swear allegiance to the British crown. The French Canadians (Quebec) started leaving, because Quebec was over populated and didn't have enough farm land to go around, while the 1800's saw the rise of industrialization in the USA, offering jobs to the many Quebecers who left.
In the early 20th century, nearly 25% of New England's population consisted of families with ties to Canada, either French Canadians or descendants of United Empire Loyalists who decided to return to the USA. In the late 19th century, nearly 20% of Canadians with European ancestry had left for the United States, primarily the Midwest and New England.
Today, an estimated 20% of British Canadians have at least one loyalist ancestor, with another 25% of Canadia having an Acadian or French Canadian ancestor. Conversely, sizeable percentage of Americans with French ancestry, have an Acadian or French Canadian ancestor, and many Americans of British ancestry, can claim to have a United Empire Loyalist ancestor, who fled the USA for Canada, only to have a descendant migrate back to the USA.
Prior to WW2, the USA / Canada were very similar culturally, and the differences were becoming smaller. In the post WW2 era, both countries essentially adopted open borders policies, and the influx of mass immigration began to widen the cultural differences, as opposed to narrowing them.
The term "American" is a political / cultural identity, as the American people are just a mixture of other groups, so many Americans identify with whatever their ancestors were. In my case, that would be French Canadians, German Silesians / Pommeranians / Hessians / Hanovarians, and Karelian Finns.
He's like the founder of the majapahit empire pretty much... Do you have better options?
