That Stephan Thernstrom’s Poverty and Progress is widely regarded as a classic is clear from the very fact that a symposium of this type is being held. Nor is the book’s reputation unwarranted. Thernstrom (1964: 1) himself wrote that “one of the most glaring gaps in our knowledge of 19th century America is the absence of reliable information about the social mobility of its population, particularly at the lower and middle levels of society.” Thanks to his study of Newburyport and the many studies of other communities that his research has helped inspire, that gap in our knowledge has been narrowed and we are all the wiser. Before Thernstrom, American historians were prone to speak of large-scale upward mobility on the basis of a handful of success stories. He showed us a better way.

Some scholars, and they include admirers of Thernstrom’s work, have recently questioned both the importance of social mobility and the extent to which it influenced the minds of working people (Henretta, 1977; Katz, 1975; and Dawley, 1976). Their argument is interesting but highly conjectural. Most of us continue to believe, and rightly so, that research such as Thernstrom’s has significantly illuminated nineteenth-century American society.