The county is named for the prominent Indian nation in the south. The county was established in 1851 and originated in 1853.

The county seat in the early stages of the county was located at Bradford, named after the chief of the Chickasaw Indian tribe. A plain log cabin, erected at a cost of $1,840, was used as the first courthouse. In the spring of 1857 the county seat was moved to New Hampton, a town more centrally located in the county. Following this there were several attempts to remove the county seat from New Hampton. Some county seat bidders were Fredericksburg, Bradford, and Forest City. All were unsuccessful in gaining the county seat.

In 1865 the first courthouse in New Hampton was completed. In 1876 an addition was completed on this building. The entire building was totally destroyed in a fire on March 26, 1880. Many irreplaceable documents were lost, but many more were saved with the help of the "Hook & Ladder Co.," and concerned citizens. With the help of a falling mist and buckets of water, the fire was finally extinguished, with total losses estimated at $2,000.

Due to towns fighting over the location of the county seat, it was not until 1881 that the central portion of a new courthouse was completed at New Hampton. The third courthouse cost $10,500 to complete; New Hampton paid $5,000 of the cost. The building was made of brick and stone. The inside was trimmed with black walnut and ash. In 1905 a wing was added on at a cost of $4,219, and one year later a second wing was completed with a cost of $200.

The current courthouse was completed in 1929 at a cost of $134,000. Architects for the courthouse were Ralston and Ralston of Waterloo, and it was constructed by Tarazar Construction Co. of Albert Lea, Minnesota.