The term American society is used here to refer to the society of the United States of America. This conventional usage is brief and convenient and implies no lack of recognition for other societies of North, Central, and South America.

Boundaries of modern national societies are permeable and often socially and culturally fuzzy and changeable. Lines on maps do not take into account the cross-boundary flows and linkages of trade, tourists, information, workers, diseases, military arms and personnel, ethnic or linguistic affiliations, and the like. As a large, heterogeneous country, the United States well illustrates such interdependence and cultural diversity.

During the second half of the twentieth century it became increasingly plain that an understanding of American society required analysis of its place in a global system. National societies have become highly interdependent through extensive flows of capital, technology, goods and services, ideas and beliefs, cultural...