Final answer:
The Battle of the Argonne Forest ended on November 11, 1918 as part of the Meuse-Argonne Offensive, a combined offensive by the Allied Powers in World War I.
Step-by-step explanation:
The Battle of the Argonne Forest ended on November 11, 1918. It was a part of the larger Meuse-Argonne Offensive, which was a combined offensive by the Allied Powers during the final months of World War I. The offensive featured the most significant battlefield contribution by American troops and led to the German surrender. The end of the battle marked the beginning of the peace process.