As industrialism worked its changes in American society in the quarter century after the Civil War, it left visible evidence of its progress on the very face of the land. By 1890 an observer could see the modern world in such things as electric lights gleaming on asphalt-paved streets, or oil-laden barges chuffing down a river where birchbark canoes had ridden high and light less than a lifetime ago. Less visible were other alterations, no less portentous. The intellectual foundations which supported American life were changing, and some of them were disappearing as surely as the buffal