The author discusses the case of Rose Freistater, a teacher at James Monroe High School. Freistater's application for her teaching license was rejected by the New York City Board of Examiners due to overweight. Although a number of overweight and underweight teachers were rejected by the Board of Education in the ten years that the standards had existed, she was the first to appeal to the state that the qualifications were unfair. Both "Time" and "Newsweek" reported the Freistater story for over six months; then, after her final rejection it disappeared. The beliefs about health, efficiency, and the professional responsibilities of the teacher that her case reflected, however, neither began nor ended there. Much has been written about educators' development of a disciplinary body of knowledge in the thirty years preceding World War I and, more specifically, about the benefits, limitations, and results of this disciplinary knowledge. Many of the watersheds of urban Progressive reform--including the introduction of intelligence testing, the implementation of a vocational curriculum, and the development of physical education and life-adjustment courses in the high schools--focused on reorganizing increasingly heterogeneous and expansive classrooms. With Progressive reform, teachers were no longer "natural" caretakers but professional ones equipped with the scientific methods and theories by which to best understand and serve children. This essay reveals the experts' efforts to discipline the teacher in interwar America by attending to three important events that have been largely overlooked in the history of teacher professionalization: interwar experts' fascination with teacher types; their attempts to redress the unfashionable teacher; and the concern that a professional rhetoric of health expressed over teachers' individual and collective bodies. (Contains 2 figures and 70 footnotes.)