Prior to the settlement of the county, a tribe of Indians bearing the name of Chickasaw occupied it. The chief of this tribe was called Bradford. The county and the town of Chickasaw were named after this Indian tribe and the township of Bradford after its chief.
Chickasaw County was first created as a political subdivision of the State of Iowa on January 15, 1851. On January 12, 1853, this county was attached to Fayette County for election, revenue and judicial purposes. But on the 31st of June 1853, in answer to a petition circulated by a number of residents of the county stating that on the first Monday in August an election was to be held in the town of Bradford for the sake of organizing Chickasaw County, and for the purpose of electing its officials. The officers were duly elected at this date, but due to some misunderstanding, they were not given the power to perform the functions of their respective offices.
On April 3, 1854, another election was called at which time the officials were properly elected, including James Lyon, county judge; S. C. Goddard, county clerk; John Campbell, treasurer and recorder; D. A. Babcock, prosecuting attorney; Andy Sample, sheriff. The first court house was built at Bradford in 1854 and was the primitive log house, without a ceiling, common to the architecture of those early days and in it was held all the public meetings.
There were struggles for political supremacy for the county seat. In 1857, the county seat was moved from Bradford and relocated to New Hampton at the geographical center of the county.
The first New Hampton courthouse was erected in 1865 and burned down on the evening of March 26, 1880. At the January session, 1881, the plan and bid of Louis Brown for $10,000 was accepted. The second court house was built of brick and stone. In 1891, a jail was erected which furnished a home for the sheriff and his family as wells as for the prisoners. Additions were made to it in 1905 and 1906 at additional costs of $4,219 and $4,200 respectively. This courthouse served the county for 47 years and on Friday, October 26, 1928 it was destroyed by a fire. The vaults, safes and their contents came through all right as did the filing cabinets and book shelving. The insurance on the old building and equipment amounted to $30,783.88. On March 15, 1930, county officials moved into the new and present court house which cost $134,000 to construct.