This volume, prepared as a work of reference and an aid to research, is concerned with the organization and disposition of United States Army ground forces that opposed the Japanese during World War II. The area covered includes Alaska, the islands of the central and South Pacific, Australia, New Guinea, New Zealand, the Philippines, Okinawa, China, Burma, and India. The period covered is 7 December l94l, the date of the attack on Pearl Harbor, through 15 August 1945, the date of cessation of hostilities in the Pacific. Unless otherwise indicated, local time has been used. With a few exceptions, only major units are included, that is, units commanded by a major general or officer of higher rank. Exceptions made were in the case of garrison forces, island commands, and similar units in order to provide a complete organizational picture in a given area. Political, strategical, tactical, logistical, geographical, and personal factors which may have influenced a commander in organizing his headquarters or employing his troops in a particular way have been omitted as being outside the province of this book. Similarly, evaluation of the performance of any individual, command organization, or method will have to be sought in the appropriate volume in the series UNITED STATES ARMY IN WORLD WAR II. Although much material was available, the researcher was often limited in his effort by the lack of some necessary data. Whenever documentation was lacking, assumptions based on experience and general documentation were made and noted as such.