When it opened in 1903, the building was four stories tall and about half of its current size. The courthouse underwent an expansion in 1938 and it now takes up the entire block bounded by Ohio, Meridian, New York, and Pennsylvania Streets. In addition, the north side of the building was expanded to include five stories.
As is typical of Beaux-Arts architecture, the courthouse features extensive use of statuary, ornate murals, grand entrances, and an elevated ceiling on the first floor. The Main Cross Corridor feature and octagonal rotunda at either end, both constructed with a variety of marbles from around the world. The first-floor elevator lobby ornate bronze gates and elaborately detailed vaulted ceilings. Two marble staircases with intricate bronze balustrades lead from the first to the third floors. Classical symbols can be found throughout the building.
The murals on the southwest corner of the third floor were painted in 1935 by Indiana resident Grant Christian, under the auspices of the Treasury Relief Art Project.