After the clearing of the three German salients was completed through the Battle of St Mihiel, Marshal Foch ordered a massive three-pronged offensive directed at the exposed fortified defences of the Hindenburg Line. The southernmost arm was the Meuse-Argonne offensive, launched by a combination of French and American troops. The Americans, advancing through the Argonne Forest, met fierce resistance, whereas the French, favoured by more open terrain to the west, made rapid progress. However, after a pause to rotate fresh troops to the front line, the Americans renewed their assault and, between 14–17 October, cleared the Argonne Forest and breached the Hindenburg Line. The French by now had raced forward 20 miles (32 km) and crossed the Aisne. Meanwhile, the two more northerly offensives were also making rapid progress, liberating Lille, Douai and Cambrai. In a final success, the Meuse-Argonne offensive would capture the city of Sedan in the week before Armistice.