Studiare lingue a Seattle

The United States of America, also referred to as the United States, U.S.A., U.S., America, or the States, is a federal republic in central North America, stretching from the Atlantic in the east to the Pacific Ocean in the west. It shares land borders with Canada in the north and Mexico in the south, a marine border with Russia in the northwest, and has a collection of districts, territories, and possessions around the world. The country has fifty states, which have a level of local autonomy according to the system of federalism. A United States citizen is usually identified as an American.

The United States traces its national origin to the declaration by thirteen British colonies in 1776 that they were free and independent states. Since the mid-20th century, it has surpassed all other nations in contemporary economic, political, military, and cultural influence.

The U.S. was founded under a tradition of government with the consent of the governed under the representative democracy model. This model of government (presidential-congressional) has since been adopted by many other countries, mostly in Central America and South America.