When the United States entered the Great War in April of 1917, there were few officers with any staff training, and none had actually served on large, complex staffs in combat. This work traces the development of the staff of the AEF and describes how Pershing found the generals to command those divisions that fought on the Western Front in World War I. Many of Pershing’s generals had been colonels only a few months prior to assuming command of divisions. John J. Pershing’s task was to mold a diverse group of men into effective staff officers and into general officers to face the rigors of modern combat. How he accomplished this task, and how well the AEF did, is the focus of this work on the AEF’s command and staff structure.