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. [Sidenote: The First Corps.] [Sidenote: The Third Corps.] [Sidenote: The Fifth Corps.] [Sidenote: Reserves.] From Les Eparges around the nose of the salient at St. Mihiel to the Moselle River the line was roughly 40 miles long and situated on commanding ground greatly strengthened by artificial defenses. Our First Corps (Eighty-second, Ninetieth, Fifth, and Second Divisions) under command of Major General Hunter Liggett, restrung its right on Pont-a-Mousson, with its left joining our Third Corps (the Eighty-ninth, Forty-second, and First Divisions), under Major General Joseph T. Dickman, in line to Xivray, were to swing in toward Vigneulles on the pivot of the Moselle River for the initial assault. From Xivray to Mouilly the Second Colonial French Corps was in line in the center and our Fifth Corps, under command of Major General George H. Cameron, with our Twenty-sixth Division and a French division at the western base of the salient, were to attack three difficult hills--Les Eparges, Combres, and Amaranthe. Our First Corps had in reserve the Seventy-eighth Division, our Fourth Corps the Third Division, and our First Army the Thirty-fifth and Ninety-first Divisions, with the Eightieth and Thirty-third 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. [Sidenote: The attack on St. Mihiel begins.] [Sidenote: Breaking the barbed-wire defenses.] After four hours' artillery preparation, the seven American divisions in the front line advanced at 5 a.m., on September 12, assisted by a limited number of tanks manned partly by Americans and partly by the French. These divisions, accompanied by groups of wire cutters and others armed with bangalore torpedoes, went through the successive bands of barbed wire that protected the enemy's front line and support trenches, in irresistible waves on schedule time, breaking down all defense of an enemy demoralized by the great volume of our artillery fire and our sudden approach out of the fog. [Sidenote: The First Army takes the salient.] [Sidenote: Many prisoners and guns taken.]