The Fifteenth was the last American field army to see service in Europe during World War II, and it was the last command of General Patton. After the end of the war, the Fifteenth was given the task of collecting historical information concerning the events of the European Theater of Operations. Patton was given command of the Fifteenth in October 1945. In actuality, it was seen as a demotion from his previous command. However, in private conversations, Patton expressed that leading the Fifteenth gave him an opportunity to devle into a topic that he had been fascinated with since the age of seven-the study of war.