Up until the World War, other branches of the Army had their own specialty schools, but the infantry did not. This situation was being amended, and Middleton would be part of that change as a new faculty member of the Infantry School at Camp Benning, about nine miles from Columbus. Middleton, whose rank had reverted to his permanent rank of captain following the war, was an instructor in the new school for his first two years at Benning, and also a member of the Infantry Board, set up for research on weapons and tactics. One of his jobs on the board was to evaluate new weapons and equipment, and at one point he tested a new semiautomatic rifle which would eventually become the M-1 rifle, the standard weapon of the infantry in World War II.