Introduction

A history of the first 40 years (1958–1998) of the AAPM is presented. The Introduction contains a brief description of the scientific origins of radiation physics with specific references. The section, Early Organizations of Medical Physicists, includes a description of the formation of the HPA (Hospital Physicists Association) in the United Kingdom; the formation of RAMPS (The Radiological and Medical Physics Society of New York); and the origin of the IOMP (International Organization for Medical Physics). The section, Formation and Activities of the AAPM, was organized in decade‐length periods, and is arranged on a yearly basis. Each year begins with a portrait and brief biography of the appropriate president for that year, followed by developments and significant events during the year. The section, Specific Topics, includes essays prepared on major activities of the AAPM usually extending over many years, and better discussed in a unified manner, rather than divided in annual segments. This section contains articles on the relationship of the NCRP and the AAPM; the radiological physics centers, joint teaching committees, the formation of the Canadian Organization of Medical Physicists; a history of the incorporation events and IRS relation to the AAPM, a brief account of the contributions of Professor D. W. Kerst, Honorary AAPM member, to the field of medical physics and a history of the AAPM journal, Medical Physics . Tables of AAPM data are provided on lists of AAPM officers, lists of award recipients, the number of members by year, and the locations of annual meetings.