The Meuse-Argonne Offensive: America's Deadliest Campaign

On November 6, 1918, during WWI, on the Western Front, Germany was retreating as French and American troops cross the Meuse and move to take Sedan. From the article:

"The Meuse-Argonne Offensive: America's Deadliest Campaign
Meuse-Argonne Offensive

1.2 million men by the end of the campaign
Germany
General Georg von der Marwitz
450,000 by the end of the campaign
Casualties:
United States: 26,277 killed and 95,786 wounded
Germany: 28,000 killed and 92,250 wounded
Opening Moves
Attacking at 5:30 AM on September 26 after a prolonged bombardment by 2,700 guns, the final goal of the offensive was the capture of Sedan, which would cripple the German rail network. It was later reported that more ammunition was expended during the bombardment than had been used in the entirety of the Civil War. The initial assault made solid gains and was supported by American and French tanks.

Falling back to the Giselher line, the Germans prepared to make stand. In the center, the attack bogged down as troops from V Corps struggled to take the 500-ft. height of Montfaucon. The capture of the heights had been assigned to the green 79th Division, whose attack stalled when the neighboring 4th Division failed to execute Pershing's orders for them to turn the German's flank and force them from Montfaucon. Elsewhere, the difficult terrain slowed the attackers and limited visibility.

Seeing a crisis developing on Fifth Army's front, General Max von Gallwitz directed six reserve divisions to shore up the line. Though a brief advantage had been gained, the delays at Montfaucon and elsewhere along the line allowed for the arrival of additional German troops who quickly began to form a new defensive line. With their arrival, American hopes for a quick victory in the Argonne were dashed and a grinding, attritional battle commenced.

While Montfaucon was taken the next day, the advance proved slow and American forces were plagued by leadership and logistical issues. By October 1, the offensive had come to a halt. Traveling among his forces, Pershing replaced several of his green divisions with more experienced troops, though this movement only added to the logistical and traffic difficulties. Additionally, ineffective commanders were mercilessly removed from their commands and replaced by more aggressive officers.

Grinding Forward
On October 4, Pershing ordered an assault all along the American line. This was met with ferocious resistance from the Germans, with the advance measured in yards. It was during this phase of the fighting that the 77th Division's famed "Lost Battalion" made its stand. Elsewhere, Corporal Alvin York of the 82nd Division won the Medal of Honor for capturing 132 Germans. As his men pushed north, Pershing increasingly found that his lines were subjected to German artillery from the heights on the east bank of the Meuse.

To alleviate this problem, he made a push over the river on October 8 with the goal of silencing German guns in the area. This made little headway. Two days later he turned command of the First Army over to Lieutenant General Hunter Liggett. As Liggett pressed on, Pershing formed the Second US Army on the east side of the Meuse and placed Lieutenant General Robert L. Bullard in command.

Between October 13-16, American forces began to break through the German lines with the capture of Malbrouck, Consenvoye, Côte Dame Marie, and Chatillon. With these victories in hand, American forces pierced the Kreimhilde line, achieving Pershing's goal for the first day. With this done, Liggett called a halt to reorganize. While collecting stragglers and re-supplying, Liggett ordered an attack towards Grandpré by the 78th Division. The town fell after a ten-day battle.

Breakthrough
On November 1, following a massive bombardment, Liggett resumed a general advance all along the line. Slamming into the tired Germans, First Army made large gains, with the V Corps gaining five miles in the center. Forced into a headlong retreat, the Germans were prevented from forming new lines by the rapid American advance. On November 5, the 5th Division crossed the Meuse, frustrating German plans to use the river as a defensive line.

Three days later, the Germans contacted Foch about an armistice. Feeling that the war should continue until the German's unconditionally surrendered, Pershing pushed his two armies to attack without mercy. Driving the Germans, American forces allowed the French to take Sedan as the war came to a close on November 11.

Aftermath
The Meuse-Argonne Offensive cost Pershing 26,277 killed and 95,786 wounded, making it the largest and bloodiest operation of the war for the American Expeditionary Force. American losses were exacerbated by the inexperience of many of the troops and tactics used during the early phases of the operation. Germans losses numbered 28,000 killed and 92,250 wounded. Coupled with British and French offensives elsewhere on the Western Front, the assault through the Argonne was critical in breaking German resistance and bringing World War I to an end."