By the outbreak of the civil war, New York had been transformed from an eighteenth- into a nineteenth-century city. Its citizens bore little resemblance to the mechanics and merchants of 1830. Its political leaders were a group of self-made men attempting to govern the sprawling and diverse metropolis that had replaced the smaller and more intimate city of patricians and Liberty Boys. The government they provided was not the paternalistic one of their forebears, but an increasingly bureaucratized and growing set of municipal organizations. When reformers spoke of that “juggernaut,” the political machine, it was a recognition that urban political life had become more autonomous both of social structure and of the national political context in which it was embedded.

City politics had acquired distinctive qualities of its own, qualities that, refined and institutionalized, would be the hallmark of American urban politics for nearly a century to come. The characteristic conflict of the nineteenth- and early twentieth-century American city, the conflict of bosses and reformers, had already taken shape. The Democracy claimed the loyalty of the overwhelming majority of the city's voters. The expansion of municipal government placed at the party's disposal resources adequate for organizing that majority, and the politicians they elected, into a disciplined and centralized organization. How did this transformation – the appearance of characteristic contestants for urban power, the creation of a majority, and the development of a distinctive and autonomous city politics – come about?