The American Expeditionary Forces (AEF) were the United States Armed Forces sent to Europe in World War I. During the United States campaigns in World War I the AEF fought in France alongside French and British allied forces in the last year of the war, against Imperial German forces. The AEF helped the French Army on the Western Front during the Aisne Offensive (at Château-Thierry and Belleau Wood) in June 1918, and fought its major actions in the Saint-Mihiel and Meuse-Argonne Offensives in late 1918.