The Battle of the Colmar Pocket was a military engagement fought between Allied forces and the Wehrmacht 19th Army, from January 20 to February 9, 1945, near Colmar, in the Alsace, France, during World War II. Fighting in extremely cold weather conditions, the French 1st Army, commanded by Jean de Lattre de Tassigny, together the US XXI Corps, led by Jacob Devers, managed to defeat the German infantry units defending the Alsatian territory after three weeks of vicious combat. The Battle of the Colmar Pocket was fought with temperatures of -20º Celcius (-4 F).
Alsace and Lorraine were among the regions most bitterly defended by the German forces. The main reason for the stubborn German defenses of these regions was that Alsace and Lorraine were part of Germany (the people there spoke German) and had been taken by the French after World War I. So, they would be defended as strongly as any other German territory. By November 1944, when the German defenses in the Vosges Mountains had collapsed under the pressure of an offensive launched by the US 6th Army, a bridgehead was formed on the west bank of the Rhine. It was 40 miles (65 km) long and 30 miles (50 km) deep. While the French forces had reached the the Rhine north of the Swiss border, the US XXI Corps (7th Army) had liberated Strasbourg on November 23, 1944. These two advances reduced the German positions in southern Alsace west of the Rhine to a semi-circular-shaped bridgehead, which was centered on the town of Colmar. This bridgehead came to be known as the Colmar Pocket.
The Battle of the Colmar Pocket began in the early hours of January 20, 1945, when elements of the French 1st Army launched an attack on the German positions around Ensisheim. This attack was supported by armored units of the French 1st armored division. Nevertheless, during the night the French attack was held back when the Germans let hell broke out, severely limiting the French I Corps advance. General John W. O’Daniel’s 3rd US Infantry Division attacked to the southeast on January 22, aiming to cross the Ill River, bypass the city of Colmar to the north, and open a path for the tanks of the French 5th Armored Division to drive on the railway bridge supplying the Germans in the Colmar Pocket at Neuf-Brisach.
Despite the tenacious fight put up by the Germans, their positions were bombed by US P-47 Thunderbolt fighter-bombers which had found holes in the clouds when the weather improved a little. This made possible for both the French and American forces to resume their advance. On February 3, General Norman Cota’s 28th Division was teamed with the French armored combat command CC4 and told to take the city of Colmar. Leading with the US 109th Infantry Regiment on February 6, the infantry crossed an antitank ditch north of the city while the French armored units located a crossing point over the obstacle. Having accomplished this, the French tanks plunged into Colmar reaching the Place Rapp (Rapp Square) at 11:30 hours. Then, the shrinking German presence on the west side of the Rhine was subjected to heavy artillery fire and airstrikes carried out by US and French aircraft. Finally, on February 9 I Corps eliminated the German rearguard at Chalampé, and with no major German forces left on the west bank of the Rhine in the region of Colmar, the Germans detonated the bridge over the Rhine at Chalampe.