From the 17th to the 20th cent. migration involved individuals and families rather than nations or mass groups. The basic motive was economic pressure, as areas of low population density attracted people from high-density areas where economic opportunity was low. The desire for religious and political freedom has also been important, and national policies have played a part. In the largest international migration in history, c.65 million people migrated from Europe to North America and South America between the 17th cent. and World War II, while another 17 million went to Africa and Australia.
Nearly 12 million people, most from Mexico or Asia, migrated to the United States in the 1970s and 80s. Within the United States, migration patterns have traditionally been from east to west. Migration from north to south since the 1960s has resulted in the ascendancy of the Sun Belt, a region extending from Florida to S California. This trend has been supported by the southward migration of many blacks. Government regulation of migration became significant in the 20th cent. (see immigration).
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.