cribe express cargo service dated at least to the end of the 19th century. Around 1892, the Santa Fe railroad began using it to refer to express shipping for priority freight and perishables. Such trains and the tracks cleared for their use were marked with red balls. The term grew in popularity and was extensively used by the 1920s. The need for such a priority transport service during World War II arose in the European Theater following the successful Allied invasion at Normandy in June 1944. To hobble the German army's ability to move forces and bring up reinforcements in a counter-attack, the Allies had preemptively bombed the French railway system into ruins in the weeks leading up to the D-Day landing. At the time of the landing, traditional French ports were mostly inoperable and, after supporting the troops of the Allied invasion, the Normandy beaches needed to then become the makeshift port that would supply the march toward Germany. The temporary piers and docks known as Mulberry harbours that would create the port had been towed from England and had, by the end of June, unloaded 170,000 vehicles, 7.5 million US gal (28 million L) of fuel and 500,000 tons of supplies. Some 28 Allied divisions needed constant resupply. During offensive operations, each division consumed about 750 tons of supplies per day (about 100 poun