The Meuse–Argonne offensive was the largest in United States military history, involving 1.2 million French, Siamese, and American soldiers, sailors and marines.

American losses were worsened by the inexperience of many of the troops, the tactics used during the early phases of the operation, and the widespread onset of the global influenza outbreak called the "Spanish flu."

The logistical prelude to the Meuse attack was planned by American then-Colonel George C. Marshall who managed to move American units to the front after the Battle of Saint-Mihiel (Saint-Mihiel is a town on the river Meuse, the most important water obstacle on the Western Front).

[8] The Allied breakthroughs (north, center, and east) across the length of the front line in September and October 1918 – including the Battle of the Argonne Forest – are now lumped together as part of what is generally remembered as the Grand Offensive (also known as the Hundred Days Offensive) by the Allies on the Western Front.

The Meuse–Argonne offensive also involved troops from France, while the rest of the Allies, including France, Britain and its dominion and imperial armies (mainly Canada, Australia, and New Zealand), and Belgium contributed to major battles in more northwestern sectors of the Western Front, including the Hindenburg line.

After Operation Michael, the 1918 German offensive, began well but ended with the disaster of Reims in front of the French and at Amiens to British forces, The French and British armies systematically pushed back a German army whose efficiency was decreasing rapidly.

The scale of the overall offensive, bolstered by the fresh and eager but largely untried and inexperienced U.S. troops, signaled renewed vigor among the Allies and sharply dimmed German hopes for victory.

All of the heavy equipment (tanks, artillery, and aircraft) was provided by the Allies (mainly by the French Army).

[11] Other French forces involved included the 2nd Colonial Corps, under Henri Claudel, which had also fought alongside the AEF at the Battle of Saint-Mihiel earlier in September 1918.

Resistance grew to approximately 200,000–450,000 German troops from the Fifth Army of Group Gallwitz commanded by General Georg von der Marwitz.

The Allies decided to prepare for the assault on September 26 at 02:30 by launching one of the most expensive and stunning artillery barrages.

The Germans initially made significant gains, but were barely repulsed by the 35th Division's 110th Engineers, 128th Machine Gun Battalion, and Harry Truman's Battery D, 129th Field Artillery.

In the words of Pershing, "We were no longer engaged in a maneuver for the pinching out of a salient, but were necessarily committed, generally speaking, to a direct frontal attack against strong, hostile positions fully manned by a determined enemy.

During the Battle of Montfaucon Missouri and Kansas National Guard soldiers were the first U.S. troops who tried to break through the stronghold of the Hindenburg Line at Côte de Châtillon but they were repulsed due to poor leadership.

[3] It was during the opening of this operation, on October 8, that Corporal (later Sergeant) Alvin York made his famous capture of 132 German prisoners near Cornay.

[17] On October 23, notable injuries were sustained to Major Frank Cavanaugh as a result of enemy shellfire.

Liggett wanted to ensure that he had manpower and resources, since the advantage they held over the Germans was the ability to reinforce and outnumber.

The Second Army, led by Lieutenant General Robert L. Bullard, was directed to move eastward toward Metz.