Christmas 1944 was a pivotal time for the Allied efforts to defeat Nazi Germany. In the 6 months since the D-Day landings they had driven the Wehrmacht out of France and were poised to cross the Rhine into Germany proper. The soldiers of the Allied armies were exhausted and their supply lines were stretched to the breaking point.
While they rested, regrouped and resupplied the Germans had other plans. Hitler and his generals threw everything they had into a final offensive. The plan was to drive a wedge of men and materiel into the American lines thereby splitting the Allied armies in two and then sprinting to the Belgian coast to cut off their supplies. The attack was launched 16 December 1944.
It was a bold move born out of desperation and in the beginning they routed the Americans overrunning their positions and capturing, killing or wounding thousands. The situation was bleak as the Allied High Command scrambled to thwart the German offensive.