The United States of America was founded in 1789 and is a federal republic composed of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles (9.8 million km2) and with over 325 million people, the United States is the world's third largest country by total area and the third-most populous. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous and located in North America between Canada and Mexico.
The southeastern contiguous United States is home of the Great Smoky Mountains National Park.