The earlier courthouse, a Greek Revival building finished in 1841, burned on May 7, 1882. The county held a design competition, and Boston architect Henry Hobson Richardson won it. The Norcross Brothers began construction, and the cornerstone was laid on October 13, 1884.
The building was completed in 1888. It is arranged around an open courtyard that lets light and air reach most of the building, with a five-story tower rising from the courtyard's open side. A covered walkway known as the Bridge of Sighs links it to the old jail.
It is one of the finest examples of Romanesque Revival architecture. Richardson called it his "great achievement", and it became a National Historic Landmark in 1976.