Although linked together by the later addition of a separate passageway, Kenney Gym and Kenney Gym Annex were built as two separate structures. Their connection was not made complete until after 1914, at which time a hallway was added linking the two buildings, and they operate as a single structure today. The integrity of the [Nathan] Ricker design was not compromised in any way by the later addition of the Men's Gymnasium. On the exterior it is essentially as it was at the time of its construction. In addition, the interior of the Drill Hall has not been significantly altered.

The Drill Hall's significance lies chiefly in its large, column-free interior space. Its impressive structure, especially for 1890, displayed Ricker's talent for engineering and, specifically, truss design. It is the best example of Ricker's educational theories rendered in wood and steel. The construction of the Drill Hall preceded the University's adoption of a new Architectural Engineering curriculum in the 1890s, and it must have in part influenced the large increase of incoming architectural students after 1890. It was a visible demonstration of what the School had to offer in terms of advanced structural theories as taught by Ricker.

In 1902 the Men's Gymnasium, designed by Nelson Strong Spencer, was constructed immediately adjacent to Ricker's Drill Hall. Spencer, in addition to emulating Ticker 's style on the exterior of his building, was able to draw upon Ricker's educational methods in designing a safe and economical building while using the most up-to- materials and methods. The two buildings were actually joined after 1914, at which time the new Armory was built to replace Ricker's Drill Hall. It was then that the Drill Hall was renamed as the Gymnasium Annex. - NRHP, 19 November 1986