U.S. military power helped to bring the war to an end—a prospect at which the German government scoffed in 1917. When Kaiser Wilhelm II was warned that unrestricted submarine warfare—and the losses it would inflict on the U.S. merchant fleet—might provoke U.S. belligerence, he scribbled in a memo, "I do not care." Even if the Americans did declare war on Germany, he blustered, they were just a bunch of cowboys with an army barely worthy of the name. What use would these weaklings be against Germany's legions?
The speed and strength of the U.S. war effort wasn't a surprise only to the kaiser; it was one of the great strategic surprises of the 20th century. In April 1917, the U.S. had enormous industrial strength—some of which had been supplying the Allies with weapons and goods since 1914—and a powerful blue-water navy. But the U.S. Army was, by European standards, pitiful—not quite 140,000 men. With astonishing speed, the War Department began creating a new army from scratch to take on the Germans. Men were drafted and volunteers enlisted in unprecedented numbers. Germany had underestimated not only America's materiel superiority but also its courage and determination to win.
By spring 1918, only 287,000 U.S. combat troops were in France. But that summer, the number soared as thousands of U.S. "doughboys" completed their training and crossed the Atlantic. By August, the U.S. First Army had been created—some 500,000 men strong. German observers, many of whom had assumed that it would take years before Washington could deploy even a handful of divisions, were stunned. One German commander, Crown Prince Rupprecht of Bavaria, lamented, "The Americans are multiplying in a way we never dreamt of."
Enough Americans were finally on the Western Front to make a major contribution to the last battles of the war—often known as the Hundred Days Campaign. Gen. John "Black Jack" Pershing's forces may not have been as battle-hardened or tactically sophisticated as their British and French counterparts, but their impact was enormous. The First Army made its long-awaited decisive assault in September in the Meuse-Argonne region, aiming to drive north toward Sedan, cutting off scores of German troops and severing critical supply routes.
U.S. troops sustained heavy casualties in the opening days, but German commanders looked on with horror: The Americans, they realized, would only grow stronger over the coming months. This helped to convince Germany to give in. On October 3, 1918—a week after the Meuse-Argonne offensive began—the newly appointed German chancellor, Max von Baden, telegraphed President Woodrow Wilson to ask for an armistice and peace talks on the basis of his Fourteen Points. For the German Empire, it would be the beginning of the end.
