A further clearance was made by the Americans northwest of Château-Thierry. One of their lines ran round Hill 204, which the Germans had just evacuated, after holding it for five weeks. In Franco-American hands the hill swung the line more to the east in the track of the general advance. The movement in this direction caused the withdrawal of German forces holding the northern part of Château-Thierry. On July 21, 1918, the whole city was occupied by the French and Americans. Strong positions were established on the north of the river, bridges were thrown across, guns were brought up, and heavy firing was directed over the river to prevent German bombers from interfering with Franco-American troops crossing over. Jaulgonne was presently occupied by American troops. When the Americans crossed the Marne they discovered that the Germans sought to deceive the Allied air bombers, who were seeking out bridges and boats along the river and otherwise preventing the Germans from crossing the stream. The Americans found submerged boats and floats, held down by rocks, but so arranged that they could be made accessible for use by the Germans in short order for crossing. In some instances these floats spanned the river and were held by cables, and it required only a short time to float them. The Germans did not get a chance to use their impromptu bridges, but the French and Americans made use of the floats when they came in pursuit of the enemy. There was now a general advance from the north of the Marne, hitherto securely held by the Germans. Some fifteen kilometers north of Château-Thierry, behind a series of hills forming an almost continuous ridge, the Germans had established artillery positions, and on the hill itself their infantry waited, prepared for a stand, with machine guns. The French and Americans advanced, their backs at last to the Marne, despite the artillery fire from the hill to cover the slow retreat of the Germans. The latter continued their backward movement with sullen and stubborn rear-guard actions, leaving numbers of machine-gun nests in the path of the Franco-American movement. At times the Americans encountered the stiffest resistance, which took the form of counterattacks rather than defensive retreats. A village in this sector being reduced by the American guns, as its occupation by the Germans was imminent, the enemy was thus forced into the open, where heavy punishment was inflicted. The fighting was so fierce as almost to rob it of the suggestion that it was a rear-guard action. Nevertheless, during the intense struggle the work of moving stores was under way. With a minimum artillery fire on both sides the Americans advanced their skirmish line over yellow wheat fields, dotted with poppies, and through clumps of wood. It was Indian fighting, modernized by machine-gun work. Fighting in open order in this way brought the American line by July 22, 1918, to more than ten kilometers north of Château-Thierry, and beyond