A jet plane crosses the continental United States from east to west in about five hours. Taking off from an Atlantic coast airport, the plane is soon flying over the gentle slopes of the Appalachian Mountains. Then, for hundreds of kilometers it crosses the fertile fields of the farm belt of the great Middle West. To the north, on clear days passengers may see the five Great Lakes located between the United States and Canada. Continuing into the west, the plane flies over vast prairies and rough cattle-grazing country. Soon the snow-topped Rocky Mountains appear in the distance. After crossing these high ranges, the plane can almost glide down into the rich valleys of California and, finally, to a landing not far from the beaches of the Pacific Ocean.

The United States has long been known as a 'melting pot', because many of its people are descended from settlers who came from all over the world to make their homes in the new land. The first immigrants in American history came from England and the Netherlands. Attracted by reports of great economic opportunities and religious and political freedom, immigrants from many other countries flocked to the United States in increasing numbers, reaching a peak in the years 1880-1914. Between 1820 and 1980 the United States admitted almost 50 million immigrants.