Historians came late to the study of the American city. They lagged far behind scholars in other disciplines who, by the turn of the twentieth century, had begun to apply the tools of the social sciences to the examination of urban America and its problems. American urban history as a distinctive field of scholarly inquiry does not date much earlier than 1940, when Arthur M. Schlesinger, sr, published his landmark article on ‘The City in American History.’ Interest in the field grew rather slowly, however, and by the mid-1950s only a half-dozen or so universities offered courses in the subject. Progress in urban history research was also somewhat less than dynamic, the chief accomplishments being several fine urban biographies and a handful of monographs, notably the works of Carl Bridenbaugh on the colonial seaport towns, Oscar Handlin's study of Boston's immigrants, and Richard C. Wade's book, The Urban Frontier (1959).