Once war was declared, the army attempted to mobilize the troops very quickly. The fatigued British and French troops, who had been fighting since August 1914, sorely needed the relief offered by the American forces. In May 1917, General John Joseph "Black Jack" Pershing was designated the supreme commander of the American army in France, and the American Expeditionary Forces (AEF) were created. Pershing and his staff soon realized how ill-prepared the United States was to transport large numbers of soldiers and necessary equipment to the front, where supplies, rations, equipment, and trained soldiers were all in short supply. Since even the transport ships needed to bring American troops to Europe were scarce, the army pressed into service cruise ships, seized German ships, and borrowed Allied ships to transport American soldiers from New York, New Jersey, and Virginia. The mobilization effort taxed the limits of the American military and required new organizational strategies and command structures to transport great numbers of troops and supplies quickly and efficiently.