Following the advanced course, Middleton spent the summer as the senior instructor at a Reserve Officer Training Camp at Fort Logan, Colorado, then returned to Camp Benning for one more year as a member of the Infantry Board. Four years at Benning had been enough for him and he was ready to move on. After expressing his wishes to a senior officer, he was assigned to Fort Leavenworth in the summer of 1923, a place he had been eleven years earlier to prepare for his officer's commission.