The first court in Jasper County was held in 1846 in the hickory log cabin home of Matthew D. Springer. In 1847 a public courthouse was built of native green lumber for $87.50. This courthouse was sold and a second one was constructed in Newton for $26,600. The building was faced with white limestone and the walls were built of brick. Other architectural accents included impressive columns and a cupola that stretched 83 feet above the ground.
The third and present courthouse is made of Indiana limestone and was dedicated on April 6, 1911. The original cost was just over $200,000. Viewers of the building's Neo-Classic design with modified Georgian Colonial detail have called the courthouse "the most beautiful county capitol in Iowa". It is approximately 121 feet by 80 feet, with a 140-foot tower. The clock has four dials, which are each 8 feet high. The clock was provided through private donations. At Christmas time the exterior is fancifully decorated.
During 1986, the interior was renovated. The boardrooms and courtrooms were restored and refurbished. The dome, which had been boarded up for years, was uncovered and repaired. Additionally, the magnificent paintings around the dome were restored.