The United States of America, or the U.S.A. for short, is a federal republic composed of 50 states, 48 of them are contiguous states. There are two other states, Alaska and Hawaii, which are north and south of the contiguous states, respectively. The United States declared its independence from the British Empire in 1776 with the Declaration of Independence. They won their independence in 1783 with the Treaty of Paris. Its capital, Washington D.C. (District of Columbia) defined by imposing neoclassical monuments and buildings including the iconic ones that house the federal government's 3 branches: the Capitol, White House and Supreme Court. Though it has no official language, English and Spanish are taught in schools. It is located in North America, between its neighbors Canada and Mexico. According to "US News", the United States has been deemed 4th best country, beating Sweden but beaten by the United Kingdom (its former owner). Its population as of February 21st, 2017 is 325,636,742 being the worlds 3rd most populated country. The 9 largest cities in the United States combined is only 7.36% of the United States population (23,985,458).
The state of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The state of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea. Nine time zones are covered. The geography, climate and wildlife of the country are extremely diverse.
At 3.8 million square miles (9.8 million km2) and with over 324 million people, the United States is the world's fourth-largest country by total area (and fourth-largest by land area and the third-most populous. It is one of the world's most ethnically diverse and multicultural nations, and is home to the world's largest immigrant population. Urbanization climbed to over 80% in 2010 and leads to growing megaregions. The country's capital is Washington, D.C. and its largest city is New York City; the other major metropolitan areas, all with around five million or more inhabitants, are Los Angeles, Chicago, San Francisco, Boston, Dallas, Philadelphia, Houston, Miami, and Atlanta.
Paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century. The United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the colonies in the aftermath of the Seven Years' War led to the American Revolution, which began in 1775. On July 4, 1776, as the colonies were fighting Great Britain in the American Revolutionary War, delegates from the 13 colonies unanimously adopted the Declaration of Independence. The war ended in 1783 with recognition of the independence of the United States by Great Britain, and was the first successful war of independence against a European colonial empire. The current constitution was adopted in 1788, after the Articles of Confederation, adopted in 1781, were felt to have provided inadequate federal powers. The first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties.
The country's official language is English.