On March 28, Pershing made a brilliant surrender. He presented himself at Foch’s headquarters and begged, in French, for a place in the fight—as if the Allies had been keeping him out of it. “I have come to say to you that the American people would hold it a great honor for our troops were they engaged in the present battle,” he said. “I ask it of you in my name and in that of the American people. There is at this moment no other question than that of fighting. Infantry, artillery, aviation—all that we have—are yours to dispose of as you will.”

Wilson agreed to send 120,000 infantrymen and machine gunners to France in April but left it to Pershing to decide how long they would spend in French and British lines. Lloyd George thanked Wilson in one breath and used the next to urge Reading to keep pressing the White House. Although the Allies had survived the first wave of the offensive, there would be more. “In the circumstances,” the prime minister wrote, “everything depends upon your going beyond ordinary province of ambassador and exercising personal supervision of carrying out of pledge.”

Pershing has often been portrayed as the least cooperative of the coalition’s generals, but he was no more protective of his country’s interests than his British and French counterparts, Douglas Haig and Henri Pétain. It was Haig, not Pershing, who was to blame for the querulous period between the Supreme War Council’s call for a commander of all Allied Forces and the agreement to give the job to Foch. Committed to defending the French and Belgian ports closest to England, Haig feared being abandoned by the French if the Germans came within reach of Paris. The dispute was ended by limiting Foch’s powers. He could coordinate the strategy of the armies on the Western Front, but the French, British, Italian, and American commanders retained the right to make their own tactical decisions and the right to appeal Foch’s directives.

After consulting the Allies, Pershing sent his entire First Division west from Lorraine to Picardy, the scene of the fighting, but by the time it settled in near Beauvais, the assault had ended. The Germans had stopped after tearing a sixty-mile-wide hole in the British lines and driving a wedge through the territory where the French and British armies overlapped. Outmanned three to one, the British suffered horrendous losses (164,000 dead and wounded, 90,000 captured).

The Allies had managed to stop the offensive ten miles short of Amiens, a railway hub vital to their supply lines. As costly as the battle had been for the French and British, it stunned the Germans, who had not expected such fierce resistance. The Germans had also run into the wall that plagued nearly every offensive of the world war: the same storms of artillery fire that opened the way for the infantry left a morass of mud and craters. Soldiers on foot could make their way through, but the wheeled vehicles carrying their supplies could not.

Believing that the Germans would have another go at Amiens, the Allies strengthened their positions accordingly, but the Germans struck far to the north, in Flanders, in hopes of sweeping the British into the sea. Haig’s Special Order of the Day for April 11 would be remembered by Britons for generations: “Every position must be held to the last man; there must be no retirement. With our backs to the wall, and believing in the justice of our cause, each one of us must fight to the end.”

Secretary Baker was on the Atlantic, heading back to the United States, when Lloyd George armed Ambassador Reading for his next skirmish with the administration. “We can do no more than we have done,” he wrote. “It rests with America to win or lose the decisive battle of the war. But if it is to be won America will have to move as she has never moved before and the president must overrule at once the narrow obstinacy which would put obstacles in the way of using American infantry in the only way in which it can be used to save the situation. If she fails, disaster is inevitable. I want you to get that into the president’s mind.”

Through their ambassadors, France and Britain pressed Wilson for more than the agreed-upon 120,000 infantrymen and machine gunners, and when they failed, Wiseman appealed to House. A State Department official took Reading to the War Department, and on May 10 Baker decided to let Pershing and Foch work out an agreement.

  •  •  •  

The AEF began to make itself felt at the end of May, when one of the First Division’s infantry regiments stormed a hilltop held by the Germans at Cantigny. The Germans counterattacked multiple times (“I thought they would never cease,” wrote the division’s commander, General Robert Lee Bullard), but after five weeks, they gave up. Although small, the AEF’s victory was strategically and psychologically important. The hilltop offered an excellent view of the German lines to the north and west, and the American performance under withering fire convinced both the Allies and the Germans that Pershing’s troops would, as Bullard put it, “fight and stick.” The French bestowed lavish congratulations and medals, and the German troops who lost Cantigny were bitterly denounced by their superiors.

The fight for Cantigny had barely begun when General Erich Ludendorff launched a third offensive, along the Chemin des Dames, a ridge east of Soissons. AEF intelligence officers had warned of such an attack, but the French discounted the report and were caught off guard. Ludendorff had seen the maneuver as a prelude to a larger offensive against the British in Flanders: by luring the Chemin des Dames troops eastward, he wanted to make it impossible for them to reinforce the British. But after an easy ten-mile advance in a single day, he abandoned his Flanders plan and stayed on the path of no resistance. In five days, the Germans rolled thirty miles, all the way to Château-Thierry on the Marne. From there it was a straight run across open ground to Paris, fifty-odd miles away. Ludendorff decided to consolidate his gains near the Marne in the hope that a serious threat to Paris would force the French to surrender.

There were 722,000 American troops in France when the attack on the Chemin des Dames began, on May 27. Foch ordered five American divisions into quiet sectors held by the French in order to free experienced French troops to defend the Marne. Pershing, in response to a plea from Pétain, ordered the AEF’s Second and Third Divisions in the same direction. But at a meeting of the Supreme War Council in early June, Pershing protested the Allies’ request for infantry and more infantry. Foch threatened to take his case to the White House. Pershing was uncowed. “Refer it to the president and be damned,” he said. “He will simply refer it back to me.”

While the Supreme War Council debated at Versailles, a French officer near Château-Thierry wrote that as he and his countrymen watched endless columns of Americans moving toward the Marne, “We all had the impression that we were about to see a wonderful transfusion of blood. Life was coming in floods to reanimate the dying body of France.” The AEF’s Third Division arranged itself along the river’s south bank at Château-Thierry, where it blew up the main bridge and helped the French beat back every German attempt to cross on makeshift bridges. The Second’s fighting in and around Château-Thierry delivered the AEF’s first major victory. By coming to the aid of the French, the Americans had forced the Germans to retreat from the Marne. Winston Churchill captured the essence of the moment in his history of the war: “Half trained, half organized, with only their courage, their numbers and their magnificent youth behind their weapons, they were to buy their experience at a bitter price. But this they were quite ready to do.” Their dead and wounded numbered ten thousand.

Americans would come to think of the AEF’s victories on the Marne in June 1918 as the turning point of the war. In a sense they were. Ludendorff’s armies would never again be so close to Paris. And while the battles were minuscule compared to the engagements at Verdun and on the Somme, the Germans understood the stakes. Ludendorff believed that by crushing the Second and Third Divisions on their first big outing, he could destroy the AEF itself. He was still optimistic after Château-Thierry, but at least one German officer on the scene felt a shift in the balance of military power. The Europeans in the field were sick of war, but the troops of the Second Division were young, strong, and brave to the point of recklessness, he wrote.

By the Fourth of July, the United States had fulfilled its promise of a million-man army in France, and a million more would arrive before the war’s end. France celebrated by giving the country a holiday and renaming a major Parisian thoroughfare for President Wilson. Three thousand American soldiers paraded along the Seine, cheered at every step by Parisians on the curbs, in windows, in trees, and on rooftops. At a luncheon hosted by the American Chamber of Commerce in Paris, Captain André Tardieu, then serving as French high commissioner to the United States, catalogued the Americans’ wartime accomplishments: U.S. Navy destroyers and torpedo boats had helped the Royal Navy chase the U-boats from the seas. The ranks of the U.S. Army had grown from 200,000 to 2,500,000. Merchant shipping capacity had more than doubled. Through the U.S. Treasury, the American people had taken on a debt of billions to help the Allies and fund their own war effort. “All that the war has demanded America has accepted,” Tardieu said; “all that it has represented she has understood, and all that is required for victory she has given.”