It is architecturally important as an early Richardsonian Romanesque building in Dubuque and as a salient work of Chicago architect Willoughby James Edbrooke. It is Edbrooke's only surviving opera house, and he used its design in his design portfolio that won him the position of Supervising Architect of the U.S. Treasury Department in 1891. Its design is said to be "representative of Edbrooke's smooth exterior wall interpretation of the Richardsonian Romanesque style."
It is architecturally significant as an early Richardsonian Romanesque building in Dubuque and a notable work by Chicago architect Willoughby James Edbrooke. It is Edbrooke's only surviving opera house, and he used its design in his portfolio that secured him the position of Supervising Architect of the U.S. Treasury Department in 1891. Its design is described as "representative of Edbrooke's smooth exterior wall interpretation of the Richardsonian Romanesque style."