Although formation of the Twentieth Engineers was authorized August 15, 1917, the first assignment of enlisted men to a Headquarters detachment was Oct. 11, and it was not until a month later that the unit assumed permanent organization. All through the training period in Washington, changes in personnel were frequent, both in officers and men.

A postcard showing the Regimental HQ at Camp American University
On the back, notice the wildly inaccurate rumor that a soldier penned

Early plans for overseas movement called for headquarters to accompany the Tenth Battalion, but it was finally decided to rout the organization across with the Eighth. A small unit, in charge of Lt.-Col. Marks, were left to report the last two Battalions ready, and Headquarters, Colonel Mitchell in command, sailed with the Eighth Battalion, February 27, 1918, aboard the transport "Mt. Vernon." Twelve days later they debarked at Brest and made the customary pilgrimage to Pontanezan.

This monograph describes the structure of the higher headquarters of the 20th Engineers

Three muddy days in rest camp, and ten more at Genicart, and the Detachment reached their permanent station at Tours, the historic city on the Loire, where Headquarters of the Service of Supplies was developing. The voluminous work of co-ordinating the activities of the Regiment necessitated many increases in the strength of the detachment, men and officers being drawn from several of the battalions. Shortly before the Armistice the long-planned amalgamation of Forestry troops was consummated. By the terms of General Order 47, Hq. S. O. S., October 18, 1918, the 10th, 20th, 41st, 42nd, and 43rd Engineers were consolidated as the 20th, and the Regimental Headquarters increased in strength to 11 officers and 82 men.

The bedroll belonging to Capt. F. F. Cobb, Medical Reserve Corps

The armistice affected headquarters routine but little. It was a foregone conclusion that the unit would stay overseas to the finish, and though several of the Regimental executives managed to draw sailing orders on various terms, the detachment was practically intact when ordered south to assume charge of the fragments of the Forestry forces in the Landes.

Arriving at Pontenx, which had been in turn the base of the 11th, 4th and 10th Battalions, Headquarters picked up the rearguard of the Burnt Area and Dax contingents, and departed for the Bordeaux embarkation area late in June. The augmented force, totaling about 100 men, filtered through the delouser July 2, and boarded the transport "Santa Eliza" July 5th.

The homeward voyage was not all fair sailing. Defects in the engines had developed on the outward voyage, and when the vessel left the Gironde it was with orders to proceed to Brest and transfer its troops to another ship. Arriving at Brest, the ship shortage led the authorities to order the "Santa Eliza" to make the passage in her crippled condition, and, pausing only to fill all the staterooms assigned to the detachment non-coms with casual officers, and to quarter the non-coms in turn, in troopspace shared with a group of general prisoners, including the execrated "Hard-boiled Smith," the ship started for America, docking at New York, July 20, 1919. The outfit was demobilized at Camp Mills, their final scattering marking the dissolution of the largest, and undoubtly the best-known regiment of the United States Army.