American society was justly famed in the nineteenth century for the richness of its associational life. Indeed, as we have seen, Alexis de Tocqueville had seen this as one of the foundations of the country's success as a democracy. Yet the very ease with which social networks could form in the United States created a vulnerability that was ruthlessly exploited by a foreign network imported into the country during the great influx of migrants from southern Italy that occurred in the late nineteenth century and early twentieth: the Mafia.