NEWLY CONSTRUCTED TREADWAY PONTOON BRIDGE over the Moselle River. ] RHINELAND CAMPAIGN 15 September 1944–15 December 1944 [Illustration: RHINELAND The Allied Advance during the Rhineland Campaign 15 September 1944 to 21 March 1945] SECTION IV Rhineland Campaign 15 September-15 December 1944[3] On 15 September 1944 the Allied forces that had invaded southern France came under control of the Supreme Commander, Allied Expeditionary Force. This added the 6th Army Group to the forces opposing the enemy along the German frontier, making a total of forty-eight Allied divisions in the European Theater of Operations. In a little over three months, 6 June-15 September 1944, the Western Allies had carried their offensives from the Normandy beaches to the western borders of Germany. During the next three months little, if any, progress was made. Several factors contributed to this general slowdown. As fall and winter approached, rain, mud, and snow greatly hindered operations and made living conditions extremely trying. The terrain became more difficult since many rivers and streams had to be crossed and rough, wooded, and hilly country was encountered. Enemy resistance stiffened as the Allies reached the German border. But more important than any other single factor was the problem of supplying the large forces which had advanced so rapidly that they had outrun their supplies. During this period, as the Allies came to the West Wall and the Rhine, severe fighting took place all along the front. Some of the most difficult operations of the war in western Europe occurred during the Rhineland Campaign as battles were fought in the Arnhem area, the Schelde estuary, the Huertgen Forest, the Aachen sector, the Metz and Saar regions, and the Belfort and Saverne Gaps. On 15 December the efforts of the Allies in the Rhineland were interrupted when the enemy broke through the lines in the Ardennes, causing a shift of troops to the Ardennes to reinforce the lines there. [Illustration: FRANCE ENLISTED MAN WALKING THROUGH MUD in his bivouac area. The Allied advance was halted at the German border by poor weather conditions, difficult terrain, stiffening German resistance, and, most of all, by lack of supplies. At this time the decision was made to employ the greatest strength in the north to attain flanking bridgeheads across the lower Rhine River beyond the main fortifications of the West Wall. This area was chosen for the drive since the terrain to the south was considered unsuitable for a rapid advance because of the mountainous and forested country.] [Illustration: ENGLAND