Operation Undertone
Operation Undertone, also known as the Saar-Palatinate Offensive, was a large assault by the U.S. Seventh, Third, and French First Armies of the Sixth and Twelfth Army Groups as part of the Allied invasion of Germany in March 1945 during World War II. A force of three corps was to attack abreast from Saarbrücken, Germany, along a 75-kilometre (47 mi) sector to a point southeast of Hagenau, France. A narrow strip along the Rhine leading to the extreme northeastern corner of Alsace at Lauterbourg was to be cleared by a division of the French First Army under operational control of the Seventh Army.