Major General Walter E. Lauer was a senior United States Army officer who fought in both World War I and World War II. During World War II he commanded the 99th Infantry Division in the Battle of the Bulge. The green troops of the 99th, along with the battle-tested 2nd Infantry Division, held a key sector controlling access to Spa and Liege and large repositories of ammunition, fuel, and supplies. Despite being outnumbered by German forces at least five to one, during the Battle of Elsenborn Ridge they did not yield. It was the only sector of the American front lines during the German offensive where the Germans failed to advance.

The 99th Infantry Division briefly existed, but never deployed, in the closing days of World War I, was reconstituted as a reserve unit in 1921, was ordered into active military service in 1942, and deployed overseas in 1944. The 99th landed at the French port of Le Havre and proceeded northeast to Belgium. During the heavy fighting in the Battle of the Bulge, the unit suffered many casualties, yet tenaciously held its defensive position. In March 1945, the 99th advanced into the Rhineland, crossing the Rhine River at Remagen on March 11. After fighting in the Ruhr area, the unit moved southward into Bavaria, where it was located at the end of the war.