The small community of Montezuma was platted as the seat for Poweshiek County in 1848. The present courthouse was started in 1857 and was completed the following year. As originally built, the courthouse was Greek Revival in design. Thin, wide pilasters surround the building on all sides, and support an entablature with tri-glyphs. At the gabled entrance front, a three-story square tower supports an octagonal domed lantern. In 1890 a two-story wing was added to the rear, and in 1934 the brick building was raised to provide additional space in the basement (an act which obviously did not help the design of the building). Though compromised by these later changes, the Poweshiek County Courthouse, described by Andreas in 1875 as “handsome and commodious,” remains one of the oldest courthouses still in use in the state. It is located within the public square, south of Main Street between Third and Fourth streets.

To the east of the courthouse, on the southeast corner of Main Street and Fourth Street, is the three-story New Carroll House Hotel (1892). The design of this brick building is essentially simplified Italianate. Its two unusual features are its setback angled corner, and the wooden porch which has been carried around the corner.