The German Army’s defensive line included a salient that encompassed the town of Saint Mihiel. The American Expeditionary Force, under the command of General Pershing, requested the responsibility of attacking the salient and capturing the town. This was intended to mark the American 1st Army’s debut in combat.

The assault commenced on September 12th in a coordinated assault from three directions. The Allied forces enjoyed overwhelming air superiority, with 1,481 aircraft patrolling the skies, comprising 40% of the pilots being American. The American forces possessed 144 tanks, commanded by Major Patton, as part of a larger tank force that included over 400 tanks.

The plan was meticulously executed, effectively surprising the German forces. They were in the process of withdrawing the salient. By the morning of the second day of the battle, troops advancing from both sides of the salient had converged, and by the end of the day, all of the objectives set by the army had been achieved.

Allied casualties for that day amounted to 7,000, including 4,500 fatalities. German casualties were 22,500, with only 2,000 fatalities but 10,500 captured. This battle solidified the reputation of the American Armies as an effective fighting force.