Focusing on occupational change and mobility, current research on stratification has largely ignored some processes of structural change and mobility that are central to classical and contemporary class theories. In this paper, class mobility is assumed to depend in part on four structural changes in the organization of production: (1) a shift from agricultural to industrial forms of production; (2) a decline in self-employment and personal or family ownership of farms and businesses; (3) an expansion of the industrial working class; and (4) an expansion of the industrial manager class location. Analysis of class mobility in six capitalist societies (the United States, Great Britain, Northern Ireland, Argentina, Chile, and Bolivia) reveals that the sizeable differences among them in total class mobility can be explained largely by differences in the structure of classes. Apart from these structural differences, the societies shared essentially the same class mobility regime—one characterized by considerable rigidity of class boundaries.