Pershing’s Line of Communications: Supporting and Supplying the Troops

When the United States entered World War I on April 6, 1917, the American Regular Army stood at 130,000, a paltry number of soldiers for a nation that had just entered a global conflict. Gen. John J. Pershing, commander of the American Expeditionary Forces (AEF), arrived in France on June 13, plunging into intense reconnaissance and deliberation to determine the nature and size of the American ground forces that would be required. About a month later he approved the General Organization Project for the AEF, recommending that the United States reinforce the Allies on the Western Front with one million troops by May 1918. He cautioned that this number might go up; it eventually doubled.

Even before Pershing committed to such large numbers, he began to arrange for their sustainment. On July 5, 1917 he established the Line of Communication (LOC) to coordinate the logistics of the AEF. In February 1918 he reorganized the LOC to become the Service of the Rear (SOR), and a month later the SOR became known as the Services of Supply (SOS) after another reorganization. These successive organizations were responsible for supporting the AEF as it massively increased in size, complexity and specialization.

The LOC was based in St. Nazaire, a port city on the western coast of France, and deployed an advanced headquarters to Nevers. By March 1918 the SOS had established nine base sections centered around major ports. It also fielded an intermediate section featuring major depots and facilities, and an advance section behind the front. These sections linked the AEF together, bringing supplies to American units throughout France. The SOS established its headquarters in Tours, France about half way between St. Nazaire and Pershing’s AEF Headquarters, established in Chaumont in September 1917.

In a matter of nine months, the AEF ballooned from 129,623 American military personnel in Europe by December 1917 to more than 1.2 million by August 1918. When the Armistice ended the fighting on November 11, 1918, more than two million American military personnel had arrived in Europe. This force was over fifteen times the size of the entire U.S. Army when the United States entered the war.

Getting supplies from the United States to this huge military machine required a transatlantic journey, followed by rail transportation and final delivery by trucks or wagons. While a massive logistical effort a century ago, the SOS carried out its mission swiftly and efficiently. The U.S. and Allied navies battled relentlessly against German submarines, known as U-boats, to secure this massive deployment and its subsequent support. AEF logisticians added 1,000 miles of standard gauge railroad track to those already existing. It assembled 1,500 locomotives and 18,000 railroad cars with parts shipped from the United States, and refurbished 2,000 locomotives and 56,000 railroad cars already in Europe. Vast regulating stations served both as major depots and as railway yards. Fleets of trucks and wagons took up the mission of transporting supplies at the railheads where the rail lines ended.

With routes and transportation in place, massive amounts of supplies could be distributed to the AEF. American logisticians used local procurement to acquire over ten million ship tons of material in Europe. In addition, approximately 7.6 million ship tons were shipped in from the United States. As American divisions arrived in France they deployed to training areas. The SOS built over 16,000 barracks in France, and acquired more than 200 million feet of lumber. Warehousing went up as well, sufficient to store 45 days of supply for the AEF beginning in the spring of 1918. The SOS ultimately rose to a strength of more than 644,500 military and nearly 24,000 civilian personnel.

American divisions became increasingly involved in combat, peaking with the  Meuse-Argonne Offensive from September 26 – November 11, 1918. Ultimately, the AEF had massed huge quantities of guns, light tanks, planes and balloons. Depots and evacuation hospitals sprang up behind the lines, and a massive hospital center consisted of 700 buildings that occupied a floor space of 33 acres. Over 1.2 million Americans and thirty American divisions participated, supplied by up to 40,000 tons of ammunition per day.

No nation had ever deployed such large forces so far from home as the United States did during World War I, nor had one ever mobilized such massive forces so quickly from such a paltry base. The accomplishments of mobilizing America, securing the sea lanes, shipping vast forces overseas, and sustaining them in prolonged combat were unprecedented. These achievements would not have been possible without the contributions of the Line of Communication and the successor Service of the Rear and Services of Supply.

Recommended Reading

American Armies and Battlefields in Europe: A History, Guide and Reference Book (Washington DC: American Battle Monuments Commission, Government Printing Office, 1938)

Coffman, Edward M., The War to End all Wars: The American Military Experience in World War I (Lexington: University Press of Kentucky, 1998)

Dalessandro, Robert J. and Knapp, Michael G. Organization and Insignia of the American Expeditionary Force 1917-1923 (Atglen, Pennsylvania: Schiffer Military History, 2008)

Eisenhower, John S. D. Yanks: The Epic Story of the American Army in World War I (New York, Free Press, 2001)