The objective of this book is to present a systematic analysis of the American occupational structure, and, thus, of the major foundation of the stratification system in this society. Processes of social mobility from one generation to the next and from career beginnings to occupational destinations are considered to reflect the dynamics of the occupational structure. By analyzing the patterns of these occupational movements, the conditions that affect them, and some of their consequences, one attempts to explain part of the dynamics of the stratification system in the United States. The inquiry is based on a considerable amount of empirical data collected from a representative sample of over 20,000 American men between the ages of 20 and 64. The survey of "Occupational Changes in a Generation" was carried out as an adjunct to the monthly "Current Population Survey" of the Bureau of the Census. The analysis of the data collected in the survey constitutes the bulk of the material reported in the present book, although occasionally other sources are drawn on as well. As the comparative data from a variety of societies needed for refining the theory of stratification are not available in this study, it has been supplemented with data from mobility surveys of other countries.