The Battle of Aachen was a battle of World War II, fought by American and German forces in and around Aachen, Germany, between 12 September and 21 October 1944. The city had been incorporated into the Siegfried Line, the main defensive network on Germany's western border; the Allies had hoped to capture it quickly and advance into the industrialized Ruhr Basin. Although most of Aachen's civilian population was evacuated before the battle began, much of the city was destroyed and both sides suffered heavy losses.

The Battle of Hürtgen Forest was a series of battles fought from 19 September to 16 December 1944, between American and German forces on the Western Front during World War II, in the Hürtgen Forest, a 140 km2 (54 sq mi) area about 5 km (3.1 mi) east of the Belgian–German border. It was the longest battle on German ground during World War II and is the longest single battle the U.S. Army has ever fought.