The Siegfried Line was a major concern of Allied planning and operations after the breakout from Normandy. German defenses combined with Allied logistical constraints were the major considerations in the debate within the senior Allied leadership over a broad-front or narrow-front strategy. By 11 September 1944, the Allied forces were advancing on the German frontier in a relatively continuous front from Switzerland to Antwerp, with Field Marshal Bernard Montgomery's 21st Army Group in the north, General Omar N. Bradley's 12th Army Group in the center, and Lieutenant General Jacob L. Devers's U.S. 6th Army Group in the south. After extensive high-level debate, Allied theater commander General Dwight D. Eisenhower shifted logistical priority to the 21st Army Group and authorized Montgomery to conduct Operation market-garden, an effort to flank the German northern defenses, cross the Rhine River at Arnhem, and rapidly penetrate and capture the industrial heart of Germany. When the market-garden operation, which began on 17 September, failed to achieve the final objective of crossing the Rhine at Arnhem, Eisenhower returned to the broad-advance concept to maintain pressure on the German forces and penetrate the Siegfried Line defenses.
Initial contact with the West Wall was made by elements of Lieutenant General Courtney H. Hodges's First Army as it advanced to the German frontier in early September in the area north of Luxemburg. Hodges began a reconnaissance in force into the Eifel region of Germany on 14 September in an effort to sustain momentum and rapidly breach the fixed defenses. Although the defensive positions were not fully manned, initial U.S. penetrations of the Siegfried Line were blunted by German counterattacks, and the American forces paused to replenish logistical stocks. On 29 September, the First Army began a major offensive against West Wall positions around Aachen, a key defensive stronghold in the Siegfried Line, with the objective of opening a route to the Rhine River. After a vicious urban battle, the Aachen garrison surrendered on 21 October. In October and again in early November, the First Army also attempted to clear the Hürtgen Forest in an effort to open a route to the Rhine and secure the Roer River dams, which potentially allowed the German military to flood crossing areas downstream in the Roer River valley. After initial successes, aggressive German counterattacks pushed back the attackers, and the battle for the Hürtgen Forest became a bloody contest that held up the First Army. At the same time, the Ninth Army cleared the German defenses to the north and secured the west bank of the Roer River by 9 December, but it did not attempt to cross the river due to the flooding threat posed by the dams.
During September, Lieutenant General George S. Patton's Third Army fought through the Lorraine border region south of Luxembourg toward the West Wall, battling German forces that used old French defensive positions of the Maginot Line and pre–World War I fortifications (especially those around Metz) to strengthen resistance to the American advance. Patton's offensive then bogged down from a combination of the German defensive effort and logistical shortages. After resupplying and refitting in late October, the Third Army reinitiated the assault on Metz on 8 November, and the city's garrison finally surrendered on 22 November. After cleaning out the remaining German positions in Lorraine, the Third Army reached the Siegfried Line on 15 December and quickly seized several river crossings. Patton then paused the advance to resupply his forces before pushing through the West Wall and breaking out toward the Rhine in an attack planned for 19 December.
In the south, Devers's 6th Army Group fought to the upper Rhine, capturing Strasbourg on 23 November. However, the Germans continued to hold the West Wall defenses and a pocket in rough terrain around the city of Colmar. Although Devers was prepared to force the Rhine, Eisenhower ordered him to consolidate along that river and reduce the Colmar pocket.
The multiple Allied advances on the West Wall were halted on 16 December when the Germans launched an offensive in the Ardennes that became known as the Battle of the Bulge. As the Allies responded to the German drive in the Ardennes, the Germans launched a second attack out of the Colmar pocket, threatening to retake Strasbourg. Both offensives fit into the operational concept for the West Wall and provided strength for defensive operations and a base for counteroffensives against the attacking force. Although surprised, the Allies were able to counter the German attacks, and the planned Allied assaults on the Siegfried Line were only delayed.
The final series of advances through the Siegfried Line and into Germany began on 8 February 1945 with an attack from the northern flank of Montgomery's 21st Army Group by the Canadian First Army, with the mission of clearing the west bank of the lower Rhine. This attack was complemented by U.S. attacks into the Roer River valley and the Hürtgen Forest. The Roer River dams were seized on 10 February, and the west bank of the lower Rhine was cleared by 5 March. In February, after repositioning following its counterattack in the Battle of the Bulge, the Third Army began a series of attacks that penetrated the Siegfried Line and allowed an advance toward the Rhine through the Eifel region. In the 6th Army Group area, the Colmar pocket was eliminated by 9 February, and the U.S. Seventh Army captured Saarbrueken on 19 March and broke through the final West Wall defenses on 20 March. The Siegfried Line held up the Allied offensive and allowed the German army to attempt counterattacks, but once the Allied logistical system provided adequate support to the combat forces, the strength of the Allies overwhelmed the German defensive structure. Jerome V. Martin
Cole, Hugh M. U.S. Army in World War II: European Theater of Operations: The Lorraine Campaign. Washington, DC: U.S. Government Printing Office, 1950.; MacDonald, Charles B. U.S. Army in World War II: European Theater of Operations: The Siegfried Line. Washington, DC: U.S. Government Printing Office, 1963.; Weigley, Russell. Eisenhower's Lieutenants: The Campaign in France and Germany, 1944–1945. Bloomington: Indiana University Press, 1981.; Whiting, Charles. Siegfried. Lanham, MD: Cooper Square Publishers, 2001.
Jerome V. Martin