as a coordinating command. Some standardization did result from the creation of ASF. ASF laid down certain principles of organization in the 1942 Services of Supply Organization Manual, and the ASF staff divisions pressed the technical services to adopt structures similar to that of ASF headquarters, as having this simplified their own work practices. However, with the exception the Transportation Corps, the technical services resisted this, as their organizational structures had evolved to suit their individual needs. This was especially true of the way in which they organized their field installations, which reported directly to the office of their respective chief. These included procurement districts, supply depots, ports, arsenals and schools. Only the Ordnance Department had its own manufacturing plants, known as government-owned, government-operated (GOGO) plants to distinguished them from government owned, privately operated enterprises. There were 73 of these, of which 21 were for TNT and powder plants, 10 were ammonia and nitrate plants, 24 were loading plants, 12 were small arms plants, and 6 were other types. In 1943, 178 installations were operated the Ordnance Department, 113 by the Transportation Corps, 97 by the Quartermaster Corps, 92 by the Corps of Engineers, 54 the Signal Corps, 42 by the Medical Department and 32 by the Chemical Warfare Service. ASF controlled the number and size but not the organization of these installations. ASF instituted standard procedures for procurement December 1944, but this did not affect the organization of the purchasing offices, which still varied greatly. That month ASF also laid down a standard organization for all depots, but the each technical service still controlled them in accordance with its own procedures. Service Commands On 4 June 1920, the National Defense Act of 1920 abolished the old territorial divisions and replaced them with nine corps areas. Each had roughly the same population in 1920, and the idea was that each would control at least one division each of the Regular Army, National Guard and Organized Reserve. The corps areas became responsible for defending the United States against invasion by Canada or Mexico. The corps areas did not work out as well as hoped. During the 1920s and 1930s, many installations, particularly those belonging to the supply arms and services, were exempted from their control; their tactical organization failed to materialize due to budget shortfalls; and the best maneuver areas were in the IV and VIII Corps Areas. In 1932, the