The rise of the professions is a ubiquitous feature of all modern industrial societies, nowhere more so than in the United States. But the historical investigation of the creation of a credentialed society still leaves much to be desired, particularly with regard to the social history of the professions. The book analyzes the background, experiences, and strategies of lawyers, physicians, and engineers in Chicago between 1870 and 1920. Combining the extensive analysis of data on thousands of professionals with the examination of personal papers and professional journals, the study reconstructs the contours of professional lives in the bustling Midwestern metropolis. As the professions struggled to cope with the integration of a diverse membership and the effects of professional specialization, they constructed occupational communities marked by highly salient boundary lines. In creating a fundamentally new type of occupation, backed by vocational titles, expert knowledge, and state licensing, the American professions played a central role in the evolution of white-collar work in modern America.