MAP 21.3 U.S. Participation on the Western Front, 1918
When American troops reached the European front in significant numbers in 1918, the Allies and Central Powers had been fighting a deadly war of attrition for almost four years. The influx of American troops and supplies helped break the stalemate. Successful offensive maneuvers by the American Expeditionary Force included those at Belleau Wood and Château-Thierry and the Meuse-Argonne campaign.