The Johnson County Museum of History was started in 1931 by the Alexander Hamilton Chapter of Daughters of the American Revolution. The group was given a room in the southwest corner of the courthouse under the leadership of Georgia Schlosser. Through the next 30 years, the collection was managed by the Museum Committee of the DAR. The museum moved in 1963, after Miss Clara Suckow donated her house at 150 W. Madison Street. In 1988 The Historical Society, along with the County, purchased the former Masonic Temple at 135 North Main Street. The museum collection was moved into the space in 1991, after its renovations were completed. The log cabin was dismantled and moved the following year.
The Johnson County Museum of History is a hub of year-round historic and cultural event programming. In the spring, the museum hosts a fundraiser for the Historical Society, Wine and Cheese, as well as a Victorian Tea. In the summer there is a week-long History Camp that invites 4th graders to learn more about Johnson County through the ages. In the fall, the annual Heritage Day gives children and adults the chance to see historic re-enactors from both Pioneer and Civil War times, as well as historic crafts and games. Holiday events include two weekend meetings with Santa, as well as a Holiday Open House.