Click on any of the units shown below to see detailed descriptions of their locations and operations, along with photographs and images of some of their uniforms and equipment.

Note: Most of the text of this article comes from "TWENTIETH ENGINEERS -- FRANCE -- 1917-1918-1919"

The back-bone of the construction forces of the Service of Supplies was formed of 5 regiments of Engineers-Railway Engineers (the 15, 16th, 17, and 18th) and Forestry Engineers (20th). Other regiments, such as the 11th, 23rd, 25th, 33rd, 55th, 32nd, 106th, 109th, 309th, 311th, 312th, 318th, 319th, and many other regiments and battalions performed valuable service in the S.O.S. But the distinction of being the mainstay regiments has been accorded to these five organizations, both because of their early arrival and long service and because of the fine work they accomplished, under conditions fraught with difficulties, during the first winter of the A. E. F. in France. The 15th Engineers, under the command of Col. Edgar Jadwin, arrived at Vierson on the 28th of July, 1917; the 17th Engineers arrived at St. Nazaire August 17; the 16th arrived at Is-sur-Tille August 26th; the 18th landed at Bordeaux August 20; the 10th (later merged with all forest troops in the 20th) arrived at Nevers October 9, under the command of Col. J. A. Woodruff; and the vanguard of the 20th arrived November 28.

With enormous increase in the strength of the American Expeditionary Forces, these regiments saw the work behind the lines expand to embrace great undertakings, the strength of the personnel involved reaching at times a maximum of 160,000 men. After reorganizations to meet changing conditions of growth, the vast construction work was brought under one head, the Division of Construction and Forestry, which in turn functioned as four sections: Administration, General Construction, Railroads and Docks, and Forestry.

The specific projects of the D. C. and F. were production of lumber, shelter for troops, hospitalization, ports, railroads, storage depots, and roads. A total of about 17,120 barracks were built to accommodate the thousands of arriving Americans; these represented no fewer than 324 lineal miles of barracks, placed end to end. On November 11,1918, there were 280,000 hospital beds provided, of which 141,000 had been made possible by construction of new hospitals, the remaining 139,000 being in French buildings. This construction totaled 7,700 hospital barracks, or 127 lineal miles of wards. After the first week in July, 1918, there were at all times at leas 50,000 beds in excess of requirements.

1,035 miles of standard gauge railroad were completed, most of it in yards at the great depots. At Gievres, where the largest storage depot was established, 143 miles of track were laid. A total of 23,000,000 squre feet of covered storage was provided. Remount depots and veterinary hospitals accommodated 67,300 animals. A baker at Is-sur-Tille was constructed, turning out 800,000 pounds of bread daily; bakeries at Brest and Bordeaux produced 150,000 pounds per day each; and one at St. Nazaire 120,000 pounds.

A total of 15,850 kilmeters of roads, or about 9,900 miles, were worked, requiring the distribution of 1,694,000 tones of rock. Large facilities were provided for water supply, sewerage, ship berths, lighterage, electric power and light, refrigeration, oil and gas storage, etc. For these projects ver large amounts of lumber were required. The Forestry Section of the D. C. and F. furnished 75 per cent. of the lumber and ties and over 90 per cent. of the fuelwood used by the American Expeditionary Forces, both in the Service of Supplies and in the Zone of the Armies.