The Johnson County Courthouse, constructed 1879-1882, is an eclectic mix of architectural styles that defies a simple description. Among its details are elements borrowed from the Neo-Classical and Beaux Arts Classical styles. The designer, architect George W. Bunting, has been referred to as ".the most prolific designer of county courthouses to reside in Indiana." Bunting's structure succeeded four previous Johnson County Courthouses. The current building replaced an 1849 structure designed by Edwin May, architect of the Indiana State House. Like so many early courthouses, fire devastated May's design in 1874. A temporary frame structure housed the courthouse functions during the construction of the present building.
The strong classical details of the courthouse such as the pediments, modillions, columns and pilasters define the building. Horizontal bands of limestone create a striking contrast to the red brick construction. The obligatory clock tower is visible for miles, but in Johnson County, four corner towers also keep watch over the courthouse square. Franklin's square is known as a Harrisonburg plan-Lake and Vanderburgh counties display the only other examples in Indiana. This plan combines the Shelbyville and Philadelphia squares whereby allowing streets to intersect at the corners, as well as in the middle of the north and south sides.