After the Second Battle of the Marne, the Allies barely stopped to catch their breaths before they resumed their offensive against the now reeling German army.  Major attacks continued all along the front in August and September 1918: the British in the far north at Ypres and 100 miles to the south at Amiens, the French further south still between the Oise and Aisne Rivers, and the Americans at St. Mihiel. 

The American offensive at St. Mihiel was the first in which American soldiers represented the majority in the Allied force, and the first in which American General John “Black Jack” Pershing was given overall command.  Since his arrival in 1917, Pershing had fought with the French and British to preserve the organizational coherence of his American force.  They had wanted to simply plug the Americans into their lines as needed; Pershing wanted them to fight as a quasi-independent unit.  Battlefield necessity forced Pershing to compromise, but, in August 1918, General Ferdinand Foch, the French general in command of overall Allied operations, finally agreed to the formation of the 1st US Army and assigned it to take the lead at the Allies’ southernmost offensive salient at St. Mihiel. 

The American offensive proved relatively simple.  The Germans had decided to pull back even before the American attack began on 12 September.  But the short battle served as a useful training ground for many of the raw American soldiers seeing their first combat.  And even though they were facing an enemy in retreat, they still managed to take 15,000 prisoners.  

The British and French offensives further north were also successful.  And with the Germans in retreat, Foch, took aim at the railroad lines that fed the German army.  If two primary hubs, one at Aulnoye in the north and the other at Mézières near Sedan at the center of the German lines, were taken, the German army would be trapped in a pocket with its supply lines cut.

American and French forces were charged with taking Mézières.  To reach the railroad, American troops, now totaling 1.2 million, had to cross the Meuse Valley and hack their way through the Argonne Forest. The forest was an all but impenetrable tangle of trees and brush; a series of ravines and ridges provided multiple places for the Germans to turn small deployments into major defensive obstacles.  American regiments quickly lost contact with one another; one “lost battalion” was surrounded by the Germans and lost 406 of its 600 men before finally rescued.  

Another American platoon was pinned down by machine gun fire until sharpshooting Corporal Alvin York picked off the gunners one by one. He eventually ran out of rifle ammunition; when he did, eight German soldiers charged York’s position. But York simply emptied his pistol into the attacking squad.  With 28 soldiers killed by York alone, the German commander surrendered the rest of his unit—132 men—to the American corporal and his seven surviving comrades. 

York’s story was turned into a movie; most of the Meuse-Argonne campaign was filled with less dramatic, bitterly fought progress.  Yet by 10 October, the Americans had cleared the Argonne Forest and were marching toward Mézières. 

Further north, British and French offensives made similar progress.  On three separate fronts, British and French forces had the Germans in full retreat.  By mid-October the German position was hopeless and they pressed hard for the armistice that was finally signed on 11 November 1918.