The First Expeditionary Division, later designated the 1st Infantry Division, was constituted on 24 May 1917, in the Regular Army, and was organized on 8 June 1917, at Fort Jay, on Governors Island in New York harbor under the command of Brigadier General William L. Sibert, from Army units then in service on the Mexico–United States border and at various Army posts throughout the United States. The original table of organization and equipment (TO&E) included two organic infantry brigades of two infantry regiments each, one engineer battalion; one signal battalion; one trench mortar battery; one field artillery brigade of three field artillery regiments; one air squadron; and a full division train. The total authorized strength of this TO&E was 18,919 officers and enlisted men. George S. Patton, who served as the first headquarters commandant for the American Expeditionary Forces, oversaw much of the arrangements for the movement of the 1st Division to France, and their organization in-country. Frank W. Coe, who later served as Chief of Coast Artillery, was the division's first chief of staff.