With the reduction of the Marne salient, we could look forward to the concentration of our divisions in our own zone.  In view of the forth-coming operation against the St. Mihiel salient, which had long been planned as our first offensive action on a large scale, the First Army was organized on August 10 under my personal command.  While American units had held different divisional and corps sectors along the western front, there had not been up to this time, for obvious reasons, a distinct American sector; but, in view of the important parts the American forces were now to play, it was necessary to take over a permanent portion of the line.  Accordingly, on August 30, the line beginning at Port sur Seille, east of the Moselle and extending to the west through St. Mihiel, thence north to a point opposite Verdun, was placed under my command.  The American sector was afterward extended across the Meuse to the western edge of the Argonne Forest, and included the 2d Colonial French, which held the point of the salient, and the 17th French Corps, which occupied the heights above Verdun.

The preparation for a complicated operation against the formidable defenses in front of us included the assembling of divisions and of corps and army artillery, transport, aircraft, tanks, ambulances, the location of hospitals, and the molding together of all of the elements of a great modern army with its own railroads, supplied directly by our own Service of Supply, The concentration for this operation, which was to be a surprise, involved the movement, mostly at night, of approximately 600,000 troops, and required for its success the most careful attention to every detail.

The French were generous in giving us assistance in corps and army artillery, with its personnel, and we were confident from the start of our superiority over the enemy in guns of all calibers.  Our heavy guns were able to reach Metz and to interfere seriously with German rail movements.  The French Independent Air Force was placed under my command which, together with the British bombing squadrons and our air forces, gave us the largest assembly of aviation that had ever been engaged in one operation on the Western front.

From Les Eparges around the nose of the salient at St. Mihiel to the Moselle River the line was roughly forty miles long and situated on commanding ground greatly strengthened by artificial defenses.  Our 1st Corps (82d, 90th, 5th and 2d Divisions), under command of Major-Gen. Hunter Liggett, restrung its right on Pont-a-Mousson, with its left joining our 3d Corps (the 89th, 42d and 1st Divisions), under Major-Gen. Joseph T. Dickman, in line to Xivray, were to swing toward Vigneulles on the pivot of the Moselle River for the initial assault.  From Xivray to Mouilly the 2d Colonial French Corps was in line in the center, and our 5th Corps, under command of Major-Gen. George H. Cameron, with our 26th Division and a French division at the western base of the salient, were to attack three different hills—­Les Eparges, Combres and Amaramthe.  Our 1st Corps had in reserve the 78th Division, our 4th Corps the 3d Division, and our First Army the 35th and 91st Divisions, with the 80th and 33d available.  It should be understood that our corps organizations are very elastic, and that we have at no time had permanent assignments of divisions to corps.