For over a century, the city of Chicago has provided a natural laboratory for research on juvenile delinquency and child neglect and abuse. In an era of increasing globalization, it is easy to overlook the importance of local community context as a major focus of social reform and scientific investigation. A century ago, it was the city rather than the nation-state that was the key site of social agitation, political mobilization, and governmental action (Rodgers 1998). Chicago, in particular, became a symbol of the destiny of modern society. It was at "ground zero" when the forces of industrialization and immigration first hit the great cities, uprooting traditional rural communities and accelerating the spread of a highly complex and differentiated pattern of urban settlement. The social dislocations stimulated by these transformations made Chicago a leading focus of social reform during the Progressive Era and an important object of sociological investigation after World War I (Ward 1989).