By the beginning of the twentieth century, the diversity and range within the urban middle class were striking. Indeed, it makes sense to replace the idea of a single “middle class” with a confederation of “middle classes” whose members engaged in occupations requiring mental, rather than physical, skill.

Below the wealthy top tier, the much larger, much less wealthy, and increasingly diversified middle class included moderately successful industrialists and merchants as well as professionals in law, business, and medicine. As industry and technology expanded in the nineteenth century, a growing demand developed for experts with specialized knowledge, and advanced education soared in importance among the middle classes.

Industrialization expanded and diversified the lower middle class. The number of independent, property-owning shopkeepers and small business people grew, and so did the number of white-collar employees. White-collar employees owned little property and often earned no more than better-paid skilled or semiskilled workers. Yet white-collar workers were fiercely committed to the middle-class ideal of upward social mobility. The tie, the suit, the soft, clean hands that accompanied low-level retail and managerial work became important status symbols that set this group above those who earned a living through manual labor.