From 1855 to 1857 there was a dispute between Osage and Mitchell as to which town should be the county seat. A commission of delegates from other counties eventually decided on Osage. Construction of a courthouse began, but another election for the county seat was soon held and construction was delayed. It was not until the fall of 1870 when the final decision from the courts was made in favor of Osage.
The courthouse had been completed in 1858. This red brick building has a silver-topped cupola. The original cost of $25,000 was well worth it since this building still serves as the courthouse for Mitchell County.