I moved from the US to Canada (European originally), Canada on the outside looks like the US but inside it's closer to Europe from my point of view (not everybody agrees and think we're very similar).
In terms of politics and religion, US is an outlier compared to western countries, many US Democratic politicians (say "liberal" Hillary Clinton) would be considered "conservative" in Canada, we're way more "progressive" than the US. Donald Trump for example would have a big chance of being prosecuted for hate speech in Canada or taken to the Human Rights Tribunal if he was a local politician.
I know quite a few tech people in Canada who had the chance to move to the US and they wouldn't even consider it for cultural reasons, perceived violence or whatever. I know a lot of people that moved as well.
American: huh, guns are great, healthcare IF you can afford it, language #2 = spanish, hockey is a sport they play in Canada, worlds most powerful military, Trump, avg. American knows little about Canada, metric system - who needs that, good universities
Canadian: eh, no guns allowed, healthcare FREE for all, language #2 = french, hockey is the 2nd most popular religion, neighbors with country with worlds most powerful military - they'll have our back, no Trump, avg Canadians knows a little about America, metric system, good universities - taxpayer subsidized
But there are plenty of Americans that fit most of your Canadian stereotypes (see sanders's popularity among young Americans for example) and probably vice versa too.
I suspect 2 US states that are far from each other will have more cultural differences than a US state and Canadian province that are adjacent.
Gun culture is a big aspect of it; I wouldn't want my hypothetical children raised in a place where people keep handguns around 'for protection'. Conservatism; Bernie Sanders would be a centrist up here, not a liberal. The strange mania of patriotism and flag-love. The military culture with half the tax dollars spent there and politicians fighting to increase it. The absolute hatred of taxes.
It's not that all Americans are like this (or that no Canadians are) but so many are that the laws, rules and norms reflect it. The culture is much further in those directions than I want to be.
I loved living in Seattle, which is more liberal than Canada in many ways, but it's still very American.
In a nutshell: Canada was one of the first countries to legalize same-sex marriage. America was one of the last in the Western world. No one is surprised by either of these two facts.
I've been to both countries several times and I would not be able to tell if a person is American or Canadian unless they told me.