The Dubuque County Courthouse, opened in 1893, is one of the more extraordinary seats of government in the Midwest, and does not easily fit into neat architectural descriptions.
I would perhaps describe it as Renaissance Revival, but that is not satisfactory.
While it does not possess a Mansard roof, it also has some of the massing and ornamentation of the Second Empire, as well.
The cupola looks like it would be more comfortable on a Colonial Revival building!
One thing it is not is the Beaux-Arts style, which I wrote about recently for St. Louis Magazine; this courthouse still reflects the playful eclecticism of the Victorian Period, and the practitioners of the former style would have been horrified by this building!
What is also wonderfully preserved on the north side of the courthouse is the rare Egyptian Revival jail from 1857 designed by John Francis Rague, which is obviously been replaced by a more modern facility. It is not the first jail built in this style; “The Tombs,” the infamous jail in New York City built in 1838, was so named because it was modeled off of Egyptian architecture.