The concept of dangerous classes extends back nearly 200 years, originating after the social disarray of the Napoleonic Wars in Great Britain and Europe. Between 1850 and 1880, the United States discovered dangerous classes and molded the term to fit conditions in this country. Mainstream proponents of the dangerous class theory claimed that large numbers of immigrants formed a dangerous class. Social controls were imposed on dangerous classes, and reactionary practices included the expansion of police powers to preserve the social order over the need to protect individual liberty. Efforts by the criminal justice system to control dangerous classes were based on attaining a stable social order and a disciplined work force. By shifting the focus of the problem from economic manipulation and exploitation to law enforcement, however, social capital was spent on symptoms rather than on causes. The author contends that current efforts by the criminal justice system to control newly rediscovered dangerous classes have not changed significantly from past practices, that modern dangerous classes include such groups as homeless people and gangs, and that policymakers have persuaded the public certain social classes are dangerous. Contemporary efforts to deal with dangerous classes are noted, including aggressive and ambitious prosecution, legislation, and civil commitment. 42 references