I think the only valid generalization is that "no generalization is worth a hill of beans." There does seem to be a lot more social fragmentation in the U.S. than Canucks are accustomed to -- there isn't one community, but thousands upon thousands knitted together, sometimes happily and sometimes not. Gated communities are perhaps a striking symbol of that. (These are just my observations as a visitor -- no insult or political commentary intended.) I've visited the U.S. for business and pleasure, and I have family down there as well. Lots of fine, decent folks south of the border, and that's a fact; though be aware that a few are not. So the only way to gain valid knowledge is to focus on specific locations. If you ask fair-minded, open questions, you'll get direct answers; Americans aren't shy about giving their opinions. Ultimately, your stay as an expat will be easier if you locate in a community that shares some of your personal values.

As a foreign national you'll need a green card to work, so you need to have skills in a field where there is a severe shortage.

On the other hand, if you have marketable skills and are looking for opportunity, consider going west instead of south. Western Canada is absolutely booming, and the labour shortage is drawing people in from all over the world ... including the U.S. of A. Anybody who shows up with skills, a positive attitude, and a willingness to work will find themselves welcome here.