The Battle of Saint-Mihiel was a major World War I battle fought from 12 to 16 September 1918, involving the American Expeditionary Forces (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 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 American Expeditionary Forces (AEF) was a formation of the United States Armed Forces on the Western Front during World War I, composed mostly of units from the U.S. Army. The AEF was established on July 5, 1917, in Chaumont, France under the command of then-major general John J. Pershing. It fought alongside French Army, British Army, Canadian Army, British Indian Army, New Zealand Army and Australian Army units against the Imperial German Army. A small number of AEF troops also fought alongside Italian Army units in 1918 against the Austro-Hungarian Army. The AEF helped the French Army on the Western Front during the Aisne Offensive (at the Battle of Château-Thierry and Battle of Belleau Wood) in the summer of 1918, and fought its major actions in the Battle of Saint-Mihiel and the Meuse-Argonne Offensive in the latter part of 1918.