By the time XX Corps reached the Moselle in the autumn of 1944, the name “Metz” had already taken on the weight of a problem no one could solve quickly. The Ghost Corps had raced six hundred miles across France in the summer, its columns outrunning fuel and maps alike, artillery batteries jolting down narrow roads behind Patton’s tanks. The men had grown used to motion, to the heady sense that the German army was always just ahead of them, always a step behind events.

Metz ended that illusion.

The city had been a fortress since long before the United States existed. The Germans had ringed it with a belt of forts—concrete casemates and underground galleries dug into commanding hills, their guns looking down over the Moselle like a row of lidless eyes. Hitler had ordered the garrison to hold at all costs. For XX Corps, under General Walton Walker, that meant the easy part of the war was over. For XX Corps Artillery and its commander, Brigadier General Julius E. Slack, it meant the guns would have to do something they had not yet been asked to do: break a fortress that had been built precisely to withstand artillery.

The Moselle was running high when the corps arrived, swollen by autumn rains. Bridges had been dropped, and the riverbanks were a churned mix of mud, rubble, and wreckage. Infantrymen looking across at the opposite shore saw not just water, but an invisible grid of German observation posts and interlocking fires. To cross, they would need more than courage. They would need the riverbank and the far slopes plowed and replowed with American steel until, for a few critical minutes, the enemy looked away or ducked.

That was Slack’s domain.

He had been in the Army since the First World War, a West Pointer whose career had run from lonely interwar batteries to the Hollywood‑adjacent Motion Picture Service, where he had once arranged film showings and USO events with Shirley Temple, Helen Hayes, and other stars. Now, in Lorraine, there were no cameras and no red carpets—only rain, plotting boards, and the responsibility of making sure every division in the corps had the fire it needed when it needed it.

In the fields and orchards west of Metz, XX Corps Artillery spread itself like a nervous system. Heavy battalions were sited on what dry ground could be found; lighter units moved forward to support the infantry regiments probing for crossings. Wire crews ran telephone lines through ditches and hedgerows, only to see them cut by shellfire and laid again. Liaison officers shuttled between corps, divisions, and battalions, carrying fire requests and situation reports.

The weather did them no favors. Low clouds and steady rain grounded aircraft and turned every gun position into a pit. Forward observers had to work from church towers, shattered houses, and whatever high ground they could reach, peering through mist at fort outlines they knew were there more from map studies than from sight. Firing tables were one thing; getting precise steel on bunkers sunk in rock was another.

The fight for Metz unfolded in phases. First came the attempts to crack the river line—artillery rolling barrages along the banks as engineers threw bridges into the current and infantrymen pushed across in boats. German artillery and mortars responded from the forts, their rounds walking back and forth over fields and staging areas. Slack’s battalions fought counter‑battery duels they could seldom see, hunting muzzle flashes and sound patterns in the gloom.

Then, as footholds were secured east of the Moselle, the battle turned into a methodical reduction of individual strongpoints. The forts—Driant, Jeanne d’Arc, and the rest—were not simple pillboxes that could be smashed by a few well‑placed salvos. They were networks: underground barracks, armored turrets, trench lines. XX Corps Artillery learned to treat each one as a separate problem, with its own fire plan and schedule.

In a leaking command post tent, maps of the Metz ring were spread across rough tables, each fort circled and annotated with calibers, ammunition allotments, and timing. Fire plans were drawn up that looked more like medical charts than operations orders: this dosage of 155‑millimeter at H‑hour, that infusion of 105s on call, counter‑battery missions ready to slam shut on any German gun that dared show itself.

The corps history would later call this phase the “Reduction of Fortress Metz,” a phrase that made it sound neat and geometric. On the ground it felt more like wearing down a stone with blows of a hammer, each day a little more rubble, each night a little closer to the heart of the defenses. Infantry attacks probed, fell back, tried again; engineers inched forward with demolition charges; the guns fired until barrels wore and crews could have laid in the dark by touch alone.

The German garrison fought hard. Some forts held out even as the city itself began to slip from their grasp. There were days when the only visible sign of progress was a sullen column of POWs trudging back through the rain. But bit by bit the ring cracked. One fort surrendered after a sustained pounding and assault; another’s garrison slipped away under cover of darkness when continued resistance became pointless.

When Metz finally fell and the city returned to French hands, the victory was more than tactical. It broke a symbol—the idea that a fortress painstakingly strengthened over decades could stand against modern combined arms. At a ceremony in the liberated city, French authorities decorated the key American commanders: corps and division leaders, and senior staff whose decisions had made the siege work. In the crowd of uniforms, among the men whose guns had turned ramparts into broken crowns, stood Julius E. Slack and the officers of XX Corps Artillery, representatives of the quiet branch that had spent weeks turning calculations into craters.

The unit’s own history would later place Metz at the center of its story, bracketed by chapters on Normandy and Northern France on one side and the Saar‑Moselle Triangle, Trier, the Siegfried Line, the Rhine, and Austria on the other. In his introductory message, Slack told his men that from Normandy across France to Metz, over the Saar and through the Siegfried Line, across the Rhine and into Austria, they had “ably demonstrated” their superiority in mobility, communications, and firepower—a dry phrase that, in the context of Metz, meant simply this: when the corps needed a fortress broken, its artillery was equal to the task.