The United States of America is the fourth largest country in the world, in terms of area, and the third largest country, in terms of population. There are 50 states covering an area of 4 million square miles with a population of more than 281 million. The density of population greatly varies, depending on where you are in the country.

The United States of America is the world's foremost economic and military power. It is also a major source of entertainment: American TV, Hollywood films, jazz, blues, rock and rap music are primary ingredients in global popular culture.

Ethnic and racial diversity - the 'melting pot' - is celebrated as a core element of the American ideology. The 1964 Civil Rights Act outlawed racial and other discrimination, but race continues to be a live issue. The ongoing debate includes topics such as affirmative-action programs - intended to remedy past discrimination - and housing segregation.

The United States of America originated in a revolution, which separated it from the British Crown. The constitution, drafted in 1787, established a federal system with a division of powers even at the central level, which, uniquely among modern nation-states, has remained unchanged in form since its inception.

The early settlers came predominantly from the British Isles. Slaves from Africa joined them involuntarily in a second wave. Millions of Europeans constituted a third stage of immigration. Today, Asians from the Pacific Rim and Hispanics from the Americas are seeking what their predecessors wanted: political freedom and prosperity. This shift is reflected in America's interests abroad, which are now less European in focus than ever before.

American foreign policy has often mixed the idealism of its "mission" with elements of self-interest. The latter is exemplified in its international record on the environment, which has attracted criticism, and the need to maintain energy supplies, in which the United States of America is not self-sufficient.

English is spoken in different ways depending on the area of the country. Accents can vary from the sharp fast-paced speech of New York to the slow-paced drawl of Mississippi. Americans are eager to help you learn the language, so you need not hesitate in asking them to correct your speech and answer your questions. Apart from this, cassettes are available to understand and learn the language. Watching television will also help a lot in learning the US English.

Lifestyles vary greatly. It is very formal in the west when compared to the east, while in the north it is more casual than in the south. In the south the lifestyle is more religious and traditional, mainly focusing on the family. In the east and west coast it is new, varying and trendy.

Food styles and menu offerings vary greatly from place to place, largely depending on the culture of the original settlers in that area. For example, while food in Texas has a strong Mexican flavor, food in Louisiana has a Cajun or French Flavor. The recipes of the Scandinavian settlers are still maintained in far northern States, while in Northern California the cuisine has an Asian flavor.

Weather observations are taken with respect to time. By Convention, weather scientists use the twenty-four hour clock, and use one time zone, Greenwich Mean Time (GMT). This time is also known as Universal Time (UTC). To convert to local time, you must know the time difference between GMT and local time for both standard time and summertime (daylight savings time). Not all states use daylight savings time in the summer.