Final answer:
Over 1,000,000 American troops joined the battle of Argonne Forest as part of the Meuse-Argonne Offensive in World War I, contributing to the Allied victory and resulting in the German surrender.
Step-by-step explanation:
Later in the month, more than 1,000,000 American troops joined the Allies in the battle of Argonne Forest, west of Verdun. This massive influx of American soldiers was part of the Meuse-Argonne Offensive, a combined effort by the Allied powers during the final months of World War I. By the end of September 1918, U.S. forces, exceeding a million men, launched a full-scale offensive into the Argonne Forest, which became a key battleground in the concluding phase of the war. This Allied counterattack, featuring significant American involvement, was instrumental in breaking the German lines, leading to the German surrender in November 1918.