The budding is surmounted by a very large dome and cupola. In the dome is a bell weighing 3,116 pounds and a town clock installed by Israel Fowler, a Madison clock maker. The stone came from Marble Hill, a few miles south of Madison. At that time it was believed that this stone was a fine grade of marble, but it was quickly discovered that Marble Hill stone eroded easily unless kept painted. During an extensive remodeling in 1960 the two-story courtroom was sacrificed to provide an additional floor, but the exterior architecture was not altered.
Pediments appear on all four sides of the building.
Dubach seems to have altered these pediments during construction. He doubled the elevation of the pediments and possibly made the columns a bit slimmer than his original drawing indicates. The Madison courthouse shows many similarities in design with the courthouse plan shown in Lafever's Young Builder's General Instructor. These similarities indicate that Dubach had a copy of the Lafever book in his possession at the time the Madison structure was built. The dome, entablature, and cornices are similar.