George S. Patton was promoted to the rank of Captain in the Regular Army

On 15/05/1917, George S. Patton Jr. was promoted to the rank of captain in the Regular Army shortly after the United States entered World War I. At the time, Patton was serving in Washington, D.C., where he had been working in a staff capacity connected to the mobilization of American forces for overseas deployment. The promotion advanced him from first lieutenant and positioned him for expanded responsibilities as the Army rapidly organized the American Expeditionary Forces. Following his promotion, Patton joined the staff of General John J. Pershing and became commander of the Headquarters Troop for the American Expeditionary Forces. In this role, he accompanied Pershing to France in June 1917 and helped organize headquarters security and movement functions during the early establishment of the AEF. His service in this position lasted through 1917, before he later volunteered for the newly developing Tank Corps and was assigned on 10/11/1917 to help establish the American Expeditionary Forces Light Tank School in France.