In 1850 the county erected its first courthouse, a hewn-log one-and-a-half-story structure with an outside stairway providing entry to the upper floor. This temporary wood structure was replaced in 1858 by a two-story brick building that was 60 feet square. At the center of the roof of this building was a twotiered tower crowned by a small dome. In style the building combined Greek Revival and Italianate features.
During 1892–1894 a new courthouse was built by the Des Moines architectural firm of Foster and Liebbe. The design of this two-story stone building is Richardsonian Romanesque. An entrance tower appears at the center of the principal facade of the square building and there are slightly projecting pedimented pavilions on the other three elevations. The assertiveness of the tower was diminished in 1954 by the removal of its high spired roof and four corner finials.