The U. S. Army Depot Command, Japan, was organized on 1 July 1966 by U. S. Army Japan General Order No.167, dated 18 July 1966.

The U. S. Army Depot Command, Japan, often called Sagami Depot, is a former Japanese military establishment. The Sixth Arsenal of the Imperial Japanese Army was established in 1935 and later became known as the Sagami Army Arsenal. During World War II, the Sagami Arsenal was one of the largest industrial developments constructed by the Japanese Government to manufacture tanks for their armies. In addition to the construction of hundreds of buildings, elaborate tunnels and underground excavations were devised to accommodate the more critical and vulnerable activities.

The first U. S. Forces unit to occupy the Sagami Arsenal after the termination of World War II was the 5th Cavalry Regiment in September 1945. In late 1946 the regiment moved to Camp McGill, and the depot area was released to the Japanese Government. It was not until the end of 1948 that the U. S. Army again made plans to reoccupy the installation. The Engineer' Depot at Yokohama began preliminary surveys for the conversion of this facility into a supply depot in the latter part of 1948, and construction of the depot and movement of Engineer supplies into this area started in the summer of 1949. The outbreak of the Korean War in June 1950 necessitated major changes in construction plans for greater operational areas and storage facilities. This installation played a major role in the support of the Korean War. In mid-1956 the Depot was redesignated the Japan Engineer Supply Center and at the end of the same year was redesignated the U. S. Army Engineer 3upply Center, Far East.

As the result or the phasedown of U. S. Army operations directed in Japan in 1957, this installation was selected as the site for the U. S. Army General Depot, Japan with a view towards consolidating the supply operations or all technical service depots in Japan. The first unit to integrate with the General Depot was the Transportation Depot which physically moved from its location in Kawasaki. In rapid succession there followed the Quartermaster, Medical and Chemical Supply Depots from Camp Drew; Signal Supply Depot from Isogo, Yokohama; and the Ordnance Depot from Oppama and other locations. The phase-in of the U. S. Army Ordnance Depot on 1 October 1958 completed the consolidation of all technical service depots in Japan into the U. S. Army General Depot, Japan.

On 1 May 1959 the General Depot organization was discontinued and the installation renamed the U. S. Army Japan Depot Complex. The principal effect of the reorganization was to place the executive direction of the supply and maintenance activities of the technical services with the chiefs of those services at Headquarters, U. S. Army Japan. It remained in this organizational posture until the organization of the U. S. Army Depot, Japan on 11 March 1963 under General Order No.10, dated 7 Mar 1963, which discontinued the technical services logistic system at Sagami.

On 1 July 1966, the U. S. Army Depot, Japan was redesignated the U. S. Army Depot Command, Japan Simultaneously, the mission and functions of the U. S. Army Logistical Center Japan (USALCJ) were transferred to this Command. Logistical support of U. S. Forces, PACOM MAP countries, AID missions, Free World Military Assistance Forces and civil governments were thereby combined under a single command responsibility.

The former USALCJ, located at Tokorozawa city, Saitama prefecture was a Japanese Air Force Base during World War II and also the cite of the oldest airfield in Japan. The Fuchu Ordnance Depot and Tokorozawa Ordnance Sub-Depot were established in 194&to store and repair general purpose vehicles for depot stocks. In 1950, the Fuchu Ordnance mission was expanded to include the repair of heavy trucks and trailers. In February 1954, Tokorozawa Ordnance Sub-Depot was assigned. an additional mission, that of establishing an MLC Depot Repair Shop. In the fall of 1954, the headquarters of Fuchu Ordnance Depot moved to Tokorozawa and in February 1955, Tokorozawa Ordnance Sub-Depot was redesignated as Tokorozawa Ordnance Depot.

After the Korea Armistice, consolidation of certain ordnance activities was required and in September 1954 Tokorozawa Ordnance Sub-Depot was assigned the additional mission of receiving, storing, and issuing certain Class II and TV supplies and maintaining reserve storage of both major and secondary items, including theatre reserves for Japan Ordnance Command.

In October 1956, the new mission of receipt, classification, storage, maintenance-in-storage, and issue of Class II and IV ordnance supplies and stock control for material in support of. Military Defense Assistance Program (MDAP) countries was assigned.

On 15 March 1957, the Tokorozawa Ordnance Depot was recognized as the Military Assistance Program Depot in Japan with the mission expanded to include Engineer, Ordnance and Signal activities and renamed the United States Army Logistical Depot, Japan.

On 23 December 1959, this installation was designated by Department of the Army as a Military Assistance Program invent9ry control point, distribution depot, procurement activity, and materiel reb4ld operation, to be known as the United States Army Logistical Depot, Japan (USAIDJ), to support MAP, Ordnance, Engineer; and Signal equipment in the PAC~ area.

On 31 March 1962, the Ordnance rebuild shops were closed to the U.S. Army Logistical Depot, Japan, and the rebuild mission was transferred to the U.S. Army Japan Depot Complex at Sagami.

On 15 May 1962, the U. S. Army Logistical Depot, Japan was redesignated as the U. S. Army Logistical Center, Japan.

On 1 July 1964, the USALCJ supply mission was realigned with the Federal Supply Classification as a means of identifying items supplied instead of end items supported.

On 1 July 1966, the consolidation of USALCJ and the U. S. Army Depot, Japan was directed by Department of the Army. In addition to the installations at Tokorozawa and Sagami, there are also four subdepots for the storage of petroleum products and ammunition. They are: the Sasebo POL Subdepot located about 800 miles from Sagami Depot; the Akizuki Ammunition Subdepot, about 540 miles from Sagami Depot; the Tsurumi POL Subdepot, about 24 miles from Sagami Depot; and the Ikego Ammunition Subdepot, about 31 miles from the Sagami Depot. Designed by the Japanese Navy for the storage of ammunition and petroleum products, these facilities have been used by the U. S. Army since the termination of World War II. These facilities were  construconstructed during the period of l900 to 1935, and they now required extensive maintenance and repair; however, they do provide a significant portion of the U. S. Army active and reserve storage capability in the Far East. Other remote storage facilities utilized by the depot include cold storage plants, a small POL storage area, and a facility used for storing inert ammunitioncted during the period of l900 to 1935, and they now required extensive maintenance and repair; however, they do provide a significant portion of the U. S. Army active and reserve storage capability in the Far East. Other remote storage facilities utilized by the depot include cold storage plants, a small POL storage area, and a facility used for storing inert ammunition.