upon assuming command of the Panama Canal Department in 1941. The Regular Army grade of lieutenant general had been abolished at the end of World War I, but was revived in 1939 when Congress authorized the officers commanding certain important Army formations to be temporarily appointed to the grade while detailed to those positions; these commands included the four field armies and the Panama Canal and Hawaiian Departments. Numerous airmen were promoted to lieutenant general during World War II. Lieutenant generals typically commanded one of the numbered field armies or air forces; served as deputy theater commanders; or headed major headquarters staffs, administrative commands, or support organizations. Most World War II lieutenant generals were appointed to that grade in the Army of the United States, even if detailed to a position that already carried the Regular Army grade; unlike the ex officio Regular Army grade, which was lost if an officer was reassigned, the Army of the United States grade was personal to each individual, making it easier to transfer officers without inadvertently demoting them. Although most air lieutenant generals belonged to the Regular Army Air Corps, anyone could be appointed lieutenant general in the Army of the United States, including reservists and civilians; James H. Doolittle was promoted to lieutenant general as an Air Corps Reserve officer and William S. Knudsen was commissioned lieutenant general directly from civilian life. 1947–1960 (U.S. Air Force) The National Security Act of 1947 transferred all personnel in the Army Air Forces, Air Corps, and General Headquarters Air Force to the newly created United States Air Force. Lieutenant generals in the new service typically headed divisions of the Air Staff in Washington, D.C.; the unified command in Alaska; the theater air forces in Europe or the Far East; or the Air Force's top-level strategic, tactical, air defense, materiel, or transportation commands. Many early three-star commands were subsequently upgraded to four stars, and their vice commanders were elevated to three stars along with the commanders of the larger numbered air forces. All three- and four-star ranks were made ex officio by the Officer Personnel Act of 1947, meaning that a lieutenant general had to be reconfirmed in that grade every time he changed jobs. During the Korean War the Far East Air Forces (FEAF) vice commander for operations, Major General Otto P. Weyland, was slated for a three-star job in the United States but Air