By October 1918, the U.S. had more than one million men fighting in the Meuse-Argonne campaign. The Allied Expeditionary Forces' logistic corps, the Services of Supply (SOS), provided critical support to combat forces from behind the lines. A bewildering array of units served in this role, including British women from Queen Mary's Army Auxiliary Corps, African American regiments, a U.S. Marine brigade led by a legendary officer, volunteers from the Salvation Army, Chinese laborers and German prisoners of war.

The SOS kept American soldiers at the front supplied with "bullets, bandages and beans" while repairing weapons, producing vast quantities of lumber, buying horses from Spain, operating a massive railroad network, caring for the sick and wounded, fighting fires on troopships, driving trucks under enemy fire and administering a notorious prison. This book gives a full account of perhaps the most overlooked yet crucial military effort of World War I.