The United States of America is a huge country, and the distances between the major cities are long. To get around, the best way is to use one of the many airlines that serve the country, and then hire a car in whatever destination you end up in.
There are also good rail links, and the legendary Greyhound buses, and although these are much slower than flying, they are a cost effective way of getting around, that is very popular with locals and tourists alike.
Within cities, cabs, buses, and even underground trains are on hand to whisk you from one attraction to another, and are.
