This rectangular building with octagonal corner towers was initially two stories in height, but a third story was added in 1914. Italian immigrant stonemasons John Taini and G. B. “John” Cassinelli constructed the building with a crew of Chinese workers, who had come to the area as railroad laborers. The design shows to advantage Taini and Cassinelli’s skill, with dressed-stone stringcourses marking the floor divisions and linking the sills and hood molds of the segmental-arched windows. Originally, squat spires capped the corner towers, and the main building had a mansard-roofed dome. When Ayres added a third floor, he covered the main body of the building with an octagonal metal dome at the center of a hipped roof, and the towers were given low-pitched metal roofs. Ayres also added one-story porticos to the entrances, marked by paired Tuscan columns. The courthouse, badly damaged by hail in 2002, was rehabilitated with funding from the Texas Historic Courthouse Preservation Program.
A modern limestone annex, the Alicemae Fitzgerald Building (1978, Joe C. Mills), with window hoods that recall those on the original courthouse, stands at the rear of the courthouse. A three-story jail, built in 1885 on the northeast corner of the courthouse square, was expanded in 1914. Adjacent to it is a new jail and sheriff’s office (1956, Weidner and Walther Architects), with deep overhangs and an asymmetrical massing.