America has long been known as an ethnic "melting pot." Its current population is 252.5 million, made up of immigrants or their descendants from virtually every country in the world. It is believed that the first people to arriveŚfrom Siberia, more than 10,000 years agoŚwere the Native Americans or the American Indians. Today, nearly 1.5 million American Indians and Eskimos live in the United States, many on tribal lands set aside for them in 31 states.
Europe, the major source of U.S. immigration, began sending colonists to America in the early 17th century, primarily from northern and western Europe. Immigration peaked in the period from 1880 to 1920, when tens of millions of immigrants entered the United States, with the largest percentage during that period coming from southern and eastern Europe.
Black Americans, who today number 30.79 million, constitute the largest single ethnic minority in the country. They were first brought to the New World as slaves in the 17th, 18th and early 19th centuries. In the 20th century large numbers of blacks, who historically lived in the South, migrated to the large industrial cities of the North in search of jobs and a better way of life. Hispanics, who number 20.5 million and live primarily in the Southwest, are the next largest ethnic minority group in the United States. Sixty percent are Mexican-Americans with the remainder from Central and South America. The Hispanic community is extremely varied, and includes large Puerto Rican populations in many eastern cities as well as a growing Cuban-American presence in Miami, Florida. The United States' population has also absorbed nearly 6.5 million Asians (from China, Hong Kong, Japan, Laos, the Philippines, Vietnam, South Korea, Cambodia and Thailand.) Many Asian Americans live in Hawaii, where more than two-thirds of the population claim an Asian or Polynesian heritage.
Once a nation of farmers, the United States has become increasingly urban since the turn of the century. Today, 77 percent of the population lives in or near cities, and only 1.9 percent of the population lives on farms. In 1988, the United States counted 10 metropolitan areas of over one million people, and 175 cities with 100,000 or more people
Since 1930, suburbs have grown faster than the cities (as middle-class residents have left the crowded living conditions of most large cities). Suburbs are defined as residential areas within commuting distance to large cities. Most people who live in suburbs own their own homes and commute to work in the city, or they work in nearby offices and factories that have relocated to the suburbs.
Americans as a nation tend to be quite mobile. Over a five year period, one family in 10 moves to a new state. In general, the population currently is shifting south and westward. California has passed New York as the most populous state, although the metropolitan area of New York City (population: 18.1 million) remains the nation's largest, with Los Angeles second (13.7 million), and Chicago third (8.181 million).
During the period from 1945 to 1964, the number of children born in the United States increased dramatically; a total of 76 million babies were born during this period. This sharp increase became known as the "baby boom." As this group, known as the baby boomers, has grown to adulthood, it has brought significant economic, cultural and social changes to the American population.