On March 9, 1844, in response to a petition from students for the adoption of uniforms for the student body, the faculty recommended the adoption of “cadet mixed” and “Kentucky jeans” as standard student dress, but did not require the wearing of the uniform. In 1860 President Ridley reorganized the military department and introduced a system of military discipline. In 1860 and 1861, military instruction was given, under the leadership of Cadet John McMillan Brooks, who left the institution to join the Confederate army. The institution closed for the Civil War in 1862.
Following designation as Tennessee’s land-grant institution in 1869, which required the university to offer courses in military science, the trustees instituted (1870) compulsory military training for all students and instituted a system that gave the military commandant and his staff full control of student conduct. Hunter Nicholson, professor of agriculture, gave instruction in military tactics to satisfy the requirement of the Morrill Act until the work was assumed by Colonel A. S. Mariner, who volunteered his services free of charge while he was on leave from his regiment. Lieutenant Thomas T. Thornburg was the first officer assigned by the US Army, arriving in December 1872. The trustees also approved a uniform for the students, the wearing of which was required at all times, beginning in 1873. In 1875 Lieutenant A. H. Nave, a West Point alumnus, won faculty approval of a code of military regulations similar to that in use at West Point. In 1889 President Dabney proposed that the military system of government and instruction apply only to freshmen and sophomores. Endorsed by the faculty and most of the students, the trustees approved the change. The new system of student government was instituted in 1890, with the dean of the university, rather than the commandant, being in charge of student discipline.