he USA is a country in North America, consisting of 48 contiguous states and the noncontiguous states of Alaska and Hawaii. It is located south of Canada and north of Mexico. The country's total area is 3,717,796 sq mi. The capital is Washington, D.C., New York City is the largest city.

The United States has an extremely varied climate, but in general temperatures increase from north to south. The country has diverse vegetation, from tundra in northern Alaska to cypress and mangrove stands along the Gulf of Mexico. Some 23 percent of the land is forested. There are vast grassy plains in the middle of the country and desert conditions in the southwest. Animal life is also varied, with mammals, reptiles, amphibians, birds, and fish throughout. The United States is exceedingly rich in natural resources; a diversity of crops and trees grows readily. The country contains significant deposits of many important minerals, including more than one-fifth of the world's coal.

The population of the United States is 267,954,767 (1997 estimate). Whites constitute about 83 percent of the people; blacks, about 13 percent; Asians and Pacific Islanders, about 4 percent; and Native Americans, about 1 percent. Hispanics, who may also be counted among other groups, make up about 11 percent. English is the main language, but many others are important, especially Spanish. Most people are Christians. Although members of the various Protestant churches are most numerous, Roman Catholics form the largest single religious group in the United States. The major Protestant groups include the Baptists, Methodists, Presbyterians, Pentecostals, and Episcopalians. The largest non-Christian religion in the United States is Judaism. Islam, Buddhism, and Hinduism also have significant numbers of followers.

The United States has one of the world's highest standards of living. Until the late 1800s agriculture was the dominant economic activity, but then industry gained importance. The United States now leads all nations in the value of its yearly manufacturing output. Leading goods are processed foods, transportation equipment, chemicals, industrial machinery, and electronic equipment. The three chief mineral products are fuels: petroleum, natural gas, and coal. Important metals include gold, copper, iron, zinc, magnesium, lead, and silver. Farming is a small part of U.S. economic activity; however, the nation produces enough not only to meet domestic needs but also to export more farm products per year than any other nation in the world. The United States is the world's leading trading nation. Canada and Japan are its most important trade partners. Tourism is also an important part of the economy. The basic unit of currency is the United States dollar.

The United States has three separate branches of government: the legislative, executive, and judicial. Each branch has a portion of constitutional authority, creating a system of checks and balances. The executive, the president, is elected for a four-year term, with a limit of two terms. The president is commander in chief of U.S. armed forces and has a wide range of other responsibilities, from external affairs, such as the negotiation of treaties, to internal affairs, such as the preparation of an annual executive budget and economic report. Legislative powers are exercised by the Congress of the United States, which has two elective houses, the Senate and the House of Representatives. The Senate consists of 100 senators, two for each state, serving six-year terms. The House has 435 members, apportioned among the states on the basis of population, serving 2-year terms