This corps was created to control units of the Third Army engaged in large scale maneuvers in 1940,[25] in which Krueger's IX Corps conducted a series of mock battles against Walter Short's IV Corps.[26] On 27 June, Krueger became commander of the VIII Corps.[27] On 16 May 1941, he was promoted to lieutenant general, in command of the Third Army. He also became commander of the Southern Defense Command on 16 July 1941. Krueger asked for—and got—Colonel Dwight D. Eisenhower assigned to him as his chief of staff.[28]