Kenny Gym and Kenny Gym Annex / Drill Hall / Armory
The Drill Hall (also known as the Armory)  was designed in 1890 by Nathan Ricker to serve as a replacement for the Mechanic and Military Hall's aging Drill Hall.  It was later renamed as the Gym Annex and underwent additions in 1914 and 1916 totally $7,947.32.  In 1918 the Engine Annex was built as an addition to the building.  It brought the building's total space to 22,500 square feet with a cost of $47,000. 
In 1901 the Men's Gymnasium, later known as the Men's Old Gymnasium,  was designed by Ricker's student, Nelson Strong Spencer, and closely modeled after the Gymnasium Annex.  It added 34,400 square feet to the complex at a cost of $98,000.  It later underwent three renovations, 1914 and 1916 renovations by James M. White for $30,554.18,  and a 1924 renovation, also by White. 
By the Second World War, the University was facing a housing crisis and almost 1000 Navy signalmen lived in the Gym Annex, training on the adjacent Illinois Field and eating in shifts in the Illini Union. After the close of the war, the University continued to use the Gym Annex as cheap housing for up to 300 unmarried men. The advent of formal men's residence halls gradually led to the reversion of the building to a gym again. 
Both buildings were later renamed after H. E. Kenny, who counted among his 41-year career, the positions of varsity wrestling coach and Professor and Assistant Dean of the College of Physical Education . 
Ricker's involvement and influence with the complex caused it to later be listed on the National Register of Historic Places.