When I retired in 1991 my first project was to revise The Response to Industrialism, which covered the years from 1877 to 1914. These, of course, are the years we call the Gilded Age and the Progressive Era. When the University of Chicago Press asked if I would undertake a revision as part of their desire to update several books in the History of American Civilization Series, I readily agreed. I did so with some instinctive understanding that much about the book would undergo revision, but just what I did not have clearly in mind. Much had changed in the profession, and much had changed in the way I thought about that period in American history. As I worked my way through the first edition the details of those changes became more clear. And so I prepared an introduction to the revision that outlined for the reader just what had changed in my thinking over those forty years.