A century ago the United States First Army, personally commanded by General John J. Pershing, was deep in preparation for the Meuse-Argonne Offensive, the largest battle in American history that the American public today knows virtually nothing about. In his report on the Meuse-Argonne Offensive, General Pershing wrote about the preparations for the campaign:
The definite decision for the Meuse-Argonne phase of the great Allied convergent attack was agreed to in my conference with Marshal Foch and General Petain on September 2nd. It was planned to use all available forces of the First Army, including such divisions and troops as we might be able to withdraw from the St. Mihiel front.
The Army was to break through the enemy’s successive fortified zones to include the Kriemhilde-Stellung, or Hindenburg Line, on the front Brieulles-Romagne sous Montfaucon-Grandpre, and thereafter, by developing pressure toward Mezieres, was to ensure the fall of the Hindenburg Line along the Aisne River in front of the Fourth French Army, which was to attack to the west of the Argonne Forest.
A penetration of some 12 to 15 kilometres was required to reach the Hindenburg Line on our front, and the enemy’s defences were virtually continuous throughout that depth.
The Meuse-Argonne front had been practically stabilized in September, 1914, and, except for minor fluctuations during the German attacks on Verdun in 1916 and the French counter-offensive in August, 1917, remained unchanged until the American advance in 1918. The net result of the four years’ struggle on this ground was a German defensive system of unusual depth and strength and a wide zone of utter devastation, itself a serious obstacle to offensive operations.
The strategical importance of this portion of the line was second to none on the western front. All supplies and evacuations of the German armies in northern France were dependent upon two great railway systems – one in the north, passing through Liege, while the other in the south, with lines coming from Luxemburg, Thionville, and Metz, had as its vital section the line Carignan-Sedan-Mezieres.
No other important lines were available to the enemy, as the mountainous masses of the Ardennes made the construction of east and west lines through that region impracticable.
The Carignan-Sedan-Mezieres line was essential to the Germans for the rapid strategical movement of troops. Should this southern system be cut by the Allies before the enemy could withdraw his forces through the narrow neck between Mezieres and the Dutch frontier, the ruin of his armies in France and Belgium would be complete.
From the Meuse-Argonne front the perpendicular distance to the Carignan-Mezieres railroad was 50 kilometres. This region formed the pivot of German operations in northern France, and the vital necessity of covering the great railroad line into Sedan resulted in the convergence on the Meuse-Argonne front of the successive German defensive positions.
The distance between “No man’s land” and the third German withdrawal position in the vicinity of the Meuse River was approximately 18 kilometres; the distance between the corresponding points near the tip of the great salient of the western front was about 65 kilometres, and in the vicinity of Cambrai was over 30 kilometres.
The effect of a penetration of 18 kilometres by the American Army would be equivalent to an advance of 65 kilometres farther west; furthermore, such an advance on our front was far more dangerous to the enemy than an advance elsewhere.
The vital importance of this portion of his position was fully appreciated by the enemy, who had suffered tremendous losses in 1916 in attempting to improve it by the reduction of Verdun. As a consequence it had been elaborately fortified, and consisted of practically a continuous series of positions 20 kilometres or more in depth.
In addition to the artificial defences, the enemy was greatly aided by the natural features of the terrain. East of the Meuse the dominating heights not only protected his left but gave him positions from which powerful artillery could deliver an oblique fire on the western bank.
Batteries located in the elaborately fortified Argonne forest covered his right flank, and could cross their fire with that of the guns on the east bank of the Meuse. Midway between the Meuse and the forest the heights of Montfaucon offered perfect observation and formed a strong natural position which had been heavily fortified.
The east and west ridges abutting on the Meuse and Aire River valleys afforded the enemy excellent machine-gun positions for the desperate defence which the importance of the position would require him to make. North of Montfaucon densely wooded and rugged heights constituted natural features favourable to defensive fighting.
When the First Army became engaged in the simultaneous preparation for two major operations, an interval of 14 days separated the initiation of the two attacks. During this short period the movement of the immense number of troops and the amount of supplies involved in the Meuse-Argonne battle, over the few roads available, and confined entirely to the hours of darkness, was one of the most delicate and difficult problems of the war.
The concentration included 15 divisions, of which 7 were involved in the pending St. Mihiel drive, 3 were in sector in the Vosges, 3 in the neighbourhood of Soissons, 1 in a training area, and 1 near Bar-le-Due. Practically all the Artillery, Aviation, and other auxiliaries to be employed in the new operations were committed to the St. Mihiel attack and therefore could not be moved until its success was assured.
The concentration of all units not to be used at St. Mihiel was commenced immediately, and on September 13th, the second day of St. Mihiel, reserve divisions and Army Artillery units were withdrawn and placed in motion toward the Argonne front.
That part of the American sector from Fresnes-en-Woevre, southeast of Verdun, to the western edge of the Argonne Forest, while nominally under my control, did not actively become a part of my command until September 22nd, on which date my headquarters were established at Souilly, southwest of Verdun.
Of French troops, in addition to the Second French Colonial Corps, composed of 3 divisions, there was also the Seventeenth French Corps of 3 divisions holding the front north and east of Verdun.
At the moment of the opening of the Meuse-Argonne battle, the enemy had 10 divisions in line and 10 in reserve on the front between Fresnes-en-Woevre and the Argonne Forest, inclusive. He had undoubtedly expected a continuation of our advance toward Metz. Successful ruses were carried out between the Meuse River and Luneville to deceive him as to our intentions, and French troops were maintained as a screen along our front until the night before the battle, so that the actual attack was a tactical surprise.
Pershing had insisted that the American forces had to fight as a unit and not be used merely to reinforce the operations of the British and the French. Now the AEF had its chance, but against German defenses in extremely rugged terrain, and a vital area that the Germans would attempt to hold at all costs. The AEF was about to have a classic baptism by fire.