United States of America is a country consisting of 50 states, a federal district, and various outlying areas. Forty-nine of the states and the federal district (the District of Columbia) are in North America. The 50th state, Hawaii, is an island group in the Pacific Ocean. The outlying areas are in the Pacific Ocean and the Caribbean area, and include American Samoa, Guam, Northern Marianas, Puerto Rico, and Virgin Islands. This article is concerned with the United States proper—the 50 states and the District of Columbia. .

The United States is commonly called America and its people Americans. More properly, however, America applies to the entire Western Hemisphere, and Americans to all people who live there.

The United States is one of the largest and most powerful countries in the world. It is exceeded in size only by Russia, Canada, and China. Only China and India have larger populations. The United States leads the world in agricultural and industrial production and is one of the world's richest countries in mineral resources.

The nickname "Uncle Sam" is often used to refer to the United States or its government. In other countries United States citizens are often called Yankees or Yanks. (Within the United States the term Yankee applies only to Northerners, especially New Englanders.) The national bird is the bald eagle. The rose is the national flower.