The 20th Engineers was the largest regiment ever to exist in the United States Army. From its beginning in 1917, it grew to over 500 officers and 30,000 soldiers by Armistice Day in 1918. The organization included 14 battalions, with another 14 battalions and additional company-sized units attached. Its missions were among the most diverse of the American Expeditionary forces, from operating within direct combat range of German forces, to units scattered along the Spanish border; its soldiers were among the first to arrive in France, and among the last to return home. The primary function of the 20th Engineers was forestry--to produce lumber and timber for Allied forces--but its flexibility and command structure allowed for a wide range of other engineer missions.

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.

A short time after the United States declared war with Germany, plans for an adequate force of forest engineers were drawn up. Urged by the Joffre Mission to America by the British Mission by the cabled request of General Pershing, the War Department made the rapid formation of forestry troops one of its primary obligations to the American Expeditionary Forces.

The Allied lines of communication depended upon great amounts of timber and ties; docks, literage, storage facilities, shelter, hospitalization, ice-making plants, bakeries, and fuel. The front lines required lumber for dugouts, trench construction, entanglements, compounds for prisoners, bridges, and a great variety of other uses-even coffins.

The first step taken provided for the organization of the 10th Engineers (Forestry). This regiment, consisting of two battalions of three companies each, was authorized as an emergency measure May 17, 1917, and formally authorized by General Order No 78 on June 27th. The United States Forest Service assumed the task of recruiting the regiment, and many Government foresters answered the call to arms.

The Agriculture Department and its Forest Service helped the War Department recruit professional and trained foresters for the various forestry units that eventually coalesced into the 20th Engineer Regiment. Even the Chief Forester (Henry S. Graves) and Assistant Chief Forester (William B. Greeley) left the Forest Service to join the 20th Engineers. Click on the poster to the left to open a new window to see an example of a recruiting letter from Assistant Chief Forester/Major William B. Greeley, in a role of working with for both the Forest Service and the Army, to George Royce Kenfield of Holyoke, Massachusetts.

The 10th Engineers sailed from New York on the "Carpathia" on September 10, 1917, under the command of Colonel James A. Woodruff. The "Carpathia" landed at Glasgow, Scottland; from there the regiment traveled to Southampton, the across the English Channel to Le Havre, then Nevers, where the regiment was dispersed across France to conduct operations. There were some of the first American troops to serve in France.



Soldiers of the 42nd Engineers (later the 42nd, 43rd, and 44th Companies of the 20th Engineers) boarding the USS President Lincoln on May 10th, 1918. The ship landed at Brest, France on May 23rd. On its return trip to the United States, the Lincoln was torpedoed and sank on May 31st.

General Pershing quickly realized the 10th would be insufficient for the size force he envisioned for the AEF. In cable No. 27 on July 4th, 1917, and in several additional cables afterwards, he requested four additional regiments of lumbermen. This request was passed to the War College Division for further study and as a result General Order No. 108 was issued on August 15, 1917, authorizing one regimental headquarters, 10 battalions of forestry engineers of three companies each, and nine engineer service battalions of four companies each.

The 20th Engineer Regiment was formed on September 9, 1917 at American University in Washington, D.C. Major Earl S. Atkinson was in command until relieved on September 15th by Colonel W. A. Mitchell, who had been stationed in the office of the Chief of Engineers working on the regiment's organization. Due to limited capacity at American University, the battalions were organized over a stretch of time, with a few units billeted at Fort Myer and Camp Belvoir, Virginia, for short periods of time.

"European War Mobilization - 20th Regiment Engineers (Forestry) - Camp American University, Washington, D.C. - Oct. 1917"