Prior to the organization of this depot the Fifth and Sixth Regiments, the Sixth Machine Gun Battalion, the Base Battalion of the Fifth Regiment, and two replacement battalions had left the United States and had become part of the American Expeditionary Force. The Overseas Depot consisted of an administrative staff and the various sections as follows: (_a_) The specialists’ schools for the technical training of the infantry and machine gun, and the coordination of these specialists’ arms; (_b_) the tactical department for the instruction and training of overseas units in new tactical principles; (_c_) the enlisted staff school for the training of first sergeants, mess sergeants, cooks, company clerks, armorers, etc. Two French and four Canadian officers, who had abundant experience in the fighting in Europe, were assigned as advisors of the commanding officer. The basic independent unit of organization was the platoon, and the platoon therefore became the principal training unit. In the organization of this unit the scheme followed was to assure to each a certain nucleus of enlisted instructors trained in the various specialties, in addition to the platoon commanders, who were qualified to carry on the instruction along approved lines within the unit. This nucleus was taken from the graduates of the specialists’ schools of the depot. When four such platoons had been formed they were assembled into a company. The company headquarters, trained in the enlisted staff school, was added to the four platoons and the company organization was turned over to the company commander complete in all details. Battalions were likewise formed by the consolidation of companies. In every instance the platoon, company, and the battalion, carried out a regular schedule of drills and instructions under the supervision of the depot, but all administrative details were left in the hands of the company and the battalion commanders. These training schedules were made up in the tactical department, approved by the commanding officer, and were based on the most approved methods in effect at the time. In the cases of the formation of regimental organizations, of which there were two formed during the existence of the Overseas Depot, the battalions upon being formed were turned over to the regimental commander, and in this case direct supervision by the depot ceased, but all facilities on hand, such as material, officers acting in an advisory capacity, training areas, etc., directly attached to the depot, were placed at the disposal of the regimental commanders who were at all times in active liaison with the depot.