It really depends on where you are... I mean, if you're looking at sterotypes about loud people, that's probably going to be up in the North, say Boston or New York, perhaps Chicago. The crazy, liberal peoples all go to California, which is why it is now legal to smoke pot in some parts there.
As for the South, well, North Carolina is technically in the South, but we're kind of a buffer. You get the people moving down to Florida from the North that like our climate, and then the old people from Florida like to retire here as well (because of the beaches and such). Then the rednecks, in some places in North Carolina (a LOT in my hometown), are usually hunters (and own guns, yes), race trucks (and occasionally lawn mowers), and are the ones that think America is the sh*t, all of the time. They're white, own trailers, dirty trucks, and generally refuse to accept logic (at least the extreme ones, not trying to offend anybody). Don't let West Virginia fool you, it's a very Southern state.
I'm not sure about the western part of our country, or the middle states. They're usually a bit reserved, and keep a somewhat flat, Mid-Eastern (United States Mid-Eastern) accent, no y'all or "you'se guys" or anything like that. Some southern states (Missouri, for instance) has a bit of a Cajun accent, which is pretty hard to understand for even Southerners.
Conclusion: Those sterotypes are pretty right on, but only for certain parts of the country, not as a whole. If you take each part individually, then they usually share a few common traits, some 'slang' words, accent, and the like. Oh yeah, I'm also sorry if I offended anyone.
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