PROFESSOR ARTHUR M. SCHLESINGER, the Harvard historian, has written an entertaining little treatise called Learning How to Behave: A Historical Study of American Etiquette Books. It is curious and rather instructive to look at the development of the United States from the point of view of the literature of etiquette. The first manuals derived from Europe and emphasized deference to rank to the point of, in one case, admonishing the young: "If thy superior be relating a story, say not, 'I have heard it before.' . . . If he tell it not right, snigger not"; but after the Revolution, and especially after the advent of Jackson, the object became not to define class differences but to provide a set of prescriptions which would show anyone how to become a gentleman. The Southerners had, however, based their practice on seventeenth-century guides which helped the planter "to model his life on that of the English landed gentry" and "provided a fairly consistent chart of behavior . . . in emulation of the ancient ideals of Christian chivalry"; and they continued to follow this code. In the period after the Civil War, when the big fortunes were being made, a fresh crop of volumes appeared which had the purpose of orienting the newly rich among the refinements and complications of calling cards and formal dinners. There was an average of five such a year, and this continued through to 1945.