American services and supply played a crucial part in the World War II Siegfried Line campaign, which ran from the end of the pursuit of the German armies from Normandy in mid-September 1944 until December 1944, when the American forces were engulfed by the German Ardennes offensive. In August 1944, the Supreme Allied Commander, General Dwight D. Eisenhower, elected to continue the pursuit of the retreating German forces beyond the Seine and across France and Belgium to the German border instead of pausing to build up supplies and establish the line of communications as called for in the original Operation Overlord plan. The subsequent advance to the German border stretched the American logistical system to breaking point, and the advance came to a halt in mid-September.
Problems with port capacity and transportation created many shortages, but many others were the result of mismanagement and underestimating requirements. A critical shortage of winter clothing developed from a reluctance to accept new items and a failure to order adequate quantities in the mistaken belief that the war would end before they were required. The winter of 1944–1945 in Northwest Europe was unusually cold and wet, and American soldiers were not trained in how to avoid cold injury. The American forces suffered 71,000 casualties from trench foot and frostbite.
Artillery ammunition shortages that developed in the early days of the campaign increased casualties, delayed operations and lengthened the war. The specific causes of the shortage of artillery ammunition in the European Theater of Operations (ETO) in 1944 varied over time: between June and November, there was insufficient discharge capacity over the beaches and through the ports; between August and October, supply lines were overstretched and inadequate to move enough ammunition to the front lines; from November 1944 to April 1945, there was insufficient production of ammunition in the United States.