The Meuse-Argonne Offensive: America's Deadliest Campaign

On September 26, 1918, the start of the Meuse-Argonne Offensive began. An excerpt from the article:

"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."