The United States of America reaches from the Atlantic Ocean to the Pacific, though has a lot less diversity for the total area than you would find in, say, Europe. That said, different places are certainly different, and places like Chicago and California really have their own quite distinct feel - at least, they did to me.
The USA contains huge cities packed with sky scrapers along with wide, open areas that are very sparsely populated. You can travel for miles and see almost nobody (other than other cars on the road) and nothing. Some areas are very beautiful; the Grand Canyon is probably top of my list of what I have seen so far. However, public transport is a lot less well developed as a whole than in many other places (the population can afford cars, and the distances make it hard to do profitably apart from in densely populated areas), so getting out to places without a car can be difficult.
Meals are big, service is good, and there's quite a good choice of food. The proximity to Mexico means there's good Mexican good around (eating good Mexican food is one of the main things I look forward to when I visit the USA), and on the west coast there is quite a large Asian population and thus good Asian cuisine too.
