In 1845, the first courthouse was built by the county, at a place now known as Sigourney. The total cost was $218. The building, which was a hewn log house, also served as jail, schoolhouse, meeting house, public hall, and hotel.
Lancaster became the new county seat in the late 1840s and a 20 by 30 foot two-story frame structure was completed there in the summer of 1848. In the middle 1850s, the county seat was moved back to Sigourney and another courthouse was constructed. The building was completed in 1858 at a cost of $17,200. The building was remodeled several times before a fourth courthouse was erected in 1910. This courthouse, which is still used today, has a tall clock tower and cupola. It cost $150,000 to build.