We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.The United States of America — commonly referred to as the United States, the US, the USA, the US of A, America, or the States — is a constitutional federal democratic republic occupying a large part of the continent of North America. It borders Canada from the south and Mexico from the north in its main territorial area. It also contains, off the mainland, the Hawaiian islands of the Pacific Ocean and a large state northwest of Canada called Alaska that shares a sea border with the Russian Federation. In all, the country consists of fifty states, one state-neutral capital city called Washington, DC (for "District of Columbia"), and assorted smaller commonwealths and protectorates. It is so huge (third largest country in the world overall, behind Russia and Canada respectively), in fact, that it would take days on end to drive from one opposite end to the other and a flight from London to Moscow is almost 900 miles shorter than one from Los Angeles to New York. One state of the fifty, Texas, the largest state in the mainland and second largest overall, is almost three times as large as the entire United Kingdom. Alaska, the largest overall, is about the same size as The United Kingdom, France, Germany, and Japan combined. So if you're planning to come here, don't expect to hit all the widespread landmarks in one trip unless you have a lot of time to spend and don't mind paying for many flights or sitting through long car drives (there aren't all that many passenger trains anymore, aside from more local, smaller train lines that work within a city or across a fairly small set of towns). Colonized by Europeans from the 16th century onwards, thirteen of the British-ruled colonies on the eastern coast declared independence in 1776 and combined to form their own country. The new nation then expanded westwards (to the unhappiness of the previous native population that it came into conflict with), buying land from France, Britain (not Canada), Russia, and Denmark, annexing the Kingdom of Hawaii, and gaining territory from military conflicts with Mexico, Spain, and (much later) Japan. Over the course of the late 19th century to the present, the United States became a superpower and is now technically one of the most powerful countries on the planet — it is technologically advanced and possesses a large industrial base, a large military, and great financial wealth. It is one of the largest exporters of modern media, its products being seen the world over. The country's government consists of three branches, with the head of one of these (the executive branch) being commonly viewed as a main political leader: the elected President of the United States, currently Barack Obama.
— Preamble to the United States Constitution
The Parts of the United States of America
The American flag
The flag's thirteen alternating red and white stripes symbolize the original thirteen colonies that declared independence from Britain on July 4, 1776 — Connecticut, Delaware, Georgia (including northern Alabama and Mississippi), Maryland, Massachusetts Bay (including Maine), New Hampshire, New Jersey, New York, North Carolina (including Tennessee), Pennsylvania, Rhode Island and Providence Plantations, South Carolina and Virginia (including Kentucky and West Virginia) — and the fifty white stars on the blue canton reflect the Union's current composition of fifty states. In the case of a fifty-first state joining the Union (most likely Puerto Rico), there is a 51-star flag on standby.