[2] The structure was initially designed by Southwestern professor Robert Stewart Hyer (a physicist, not an architect), who was inspired by the works of H. H. Richardson.

[4] Mood-Bridwell Hall (named for university President Francis Asbury Mood) was subsequently built nearby as a student dormitory, with construction beginning in 1906 and completed in 1908.

[3] The exterior walls are made of hand-laid 18-inch (46 cm) limestone,[7] laid by builders Flume & Waterston, who had also previously done stonework for the Texas State Capitol.

[4] The main entrances are in the south facade, formed as a pair of massive stone arches set symmetrically to the sides of the central mass of the hall.

[3] One of the Cullen Building's most prominent features is its tower, which reaches up from the hall's southwest corner to form a spire overlooking the campus.

Separate from the main body of the Cullen Building and windowed on all four sides, this chamber affords an elevated view of the campus and of surrounding Georgetown.