In April 1917, the United States ended its nonintervention policy and entered World War I as an Associated Power to aid the Allies in their fight against the Central Powers. The American Expeditionary Force, fighting alongside French and British troops, provided vital manpower on the Western Front during the Aisne Offensive and participated in major actions in the Saint-Mihiel and Meuse-Argonne Offensives that turned the tide late in the war. This volume offers the first comprehensive statistical history of the American Expeditionary Force, supplying fascinating details often omitted from narrative battle summaries. After an overview of each of the actions and battles in which the AEF participated, the book chronicles the day-to-day activities of every division. This work presents the most thorough examination of the American fighting forces that made Allied victory possible.