The United States of America (USA), commonly known as the United States (U.S. or US) or America, is a country composed of 50 states, a federal district, five major self-governing territories, and various possessions. This beautiful country demands more time to explore it. At 3.8 million square miles (9.8 million km²), the United States is the world's third- or fourth-largest country by total area and slightly smaller than the entire continent of Europe's 3.9 million square miles