Our army's activities were divided into three zones: the base, the intermediate, and advance, with that of the base and the intermediate in charge of the commanding general of the Service of Supply at Tours. Every harbor of western France not occupied by the British was teeming with American effort, while Marseilles, in the Mediterranean, was caring for our increasing business which the Atlantic ports could not accommodate. The recruits for the army of the Service of Supply must keep pace with those for the army at the front. Battalions of negroes had been brought from the Southern States to act as laborers and stevedores. We were using German prisoners for labor as fast as they were captured. At Bordeaux and Saint Nazaire, particularly, among the ports, we had built long expanses of wharves and the spur tracks which connected them with systems of warehouses. The plan had been always to have reserve supplies for forty-five days at the base ports; with thirty days' at the great intermediate depot of Gièvres, where another vast system of spur tracks and warehouses had been built in open fields, and fifteen days' supplies at the regulating stations with their systems of spur tracks and warehouses where the trains were made up to meet the immediate requisitions from the front. Without any prevision as to when the war would end, with nothing certain except that we must go on preparing as if it were to last for years in order the sooner to force the end, new construction, while requirements of the present were met, must keep pace with growth. We had car and locomotive assembling shops; motor repair shops; salvage depots, remount depots, and immense areas of hospitals, with as many as eighteen thousand beds in a single area, which had been building in grim expectation of the flow of wounded from the front when we began operations on a large scale. Nurses and doctors must be in sufficient numbers for the emergency.