The title page of Wacker's Manual of the Plan of Chicago, including the subtitle, Municipal Economy. This book went through several revisions through the second decade of the twentieth century. The original 1911 edition included a very self-congratulatory chapter on the planners. This and subsequent editions, which were aimed at eighth-grade students, eliminated that chapter and included review questions at the ends of chapters. The original long lists of questions were trimmed in successive editions.