"The Americans had been given the most difficult task of all, which was to clean up the great Argonne Forest, and then sweep the fleeing Huns back, past Sedan, famous for the defeat of the second Napoleon, over the border into Germany itself. Here Hindenburg had concentrated most of his best troops, including the crack Guard regiments. He realized that the gravest peril of all lay in the "push" of this new army, which had already given such an excellent account of its fighting qualities."