The United States of America is a federal constitutional country, which consists of many overseas territories such as Washington, D.C., 50 states and Guam. Its main part is located in central North America. The first edition of the CIA's "World Survey" was from 1989 to 1996. The United States has a total area of 9.373 million square kilometers and a population of 333 million. It is an immigrant country with a common English.