The Battle of Saint-Mihiels was a major World War I battle fought from 12–15 September 1918, involving the American Expeditionary Force (AEF) and 110,000 French troops under the command of General John J. Pershing of the United States against German positions. The U.S. Army Air Service (which later became the U.S. Air Force) played a significant role in this action. This battle marked the first use of the terms "D-Day" and "H-Hour" by the Americans. The fighting was depicted in the 1927 film Wings.