think the notion of class has not had the required time to separate as clearly here as perhaps elsewhere. Most Americans can trace their roots to immigrants from the last 300 years. Someone considered "upperclass" is unlikely to immigrate to another place looking to improve their lot in life, so essentially all Americans come from a place in society that might be considered "low". The stratification of this society started quickly and the difference in education opportunity for the "haves" and "have nots" are only one indicator of a move towards classes here in the USA. That being said in actual life there are an infinite number of classes in every society with each class feeling superior or inferior depending on their economic or social position.
When my daughter (who is way too young to have a boyfreind) came home and said "Billy asked me to be his girlfriend" I was shocked not because she is too young (the reason I should have been shocked) but because I knew Billy's Father and always felt like he was not in the same class as I was. That sounds horrible and when I realized what was making me feel that way I tried to push it out of my mind, but I think it shows that the human race has an innate tendency to class everything and everyone. I think it is an unhealthy attitude, and I am doing my best not to pass it on to my children, because it is this attitude that can also lead to many forms of discrimination (be it racially or otherwise motivated) As it stands now I accept that she thinks Billy is "so it" whatever that means. Man, I hate getting old.