The relationship between the architecture of the Supreme Court and its landscaping is one of the most successful in Washington. The architect, Cass Gilbert, effectively disguised the irregular trapezoidal plot on which the building sits while totally controlling the approach, entrance, and passage through the building. The building is composed of three parts, a dominant temple of Roman derivation flanked by two wide horizontal wings. The temple, literally conceived of as the temple of justice, contains the most important functions, culminating in the Supreme Court chamber which terminates its 385-foot-long axis. The physical and symbolic pathway to this chamber begins on the plaza. A few steps above the sidewalk, a 100-foot-wide terrace—a square expanded by great apsidal ends—runs counter to the main east-west axis. The terrace is enclosed by the same low wall that surrounds the entire building and is paved in the gray and white marble pattern of alternating circles and squares seen at the Roman Pantheon. Immediately upon entering the terrace one encounters marble candelabra where low-relief panels depict Justice holding her sword and scales and the Three Fates weaving the thread of life. The bronze bases of the flagpoles there, designed by Gilbert and modeled by John Donnelly, Jr., are decorated with numerous symbols of justice (scales and swords, books, masks and torches, pens and maces) as well as the four elements (earth, air, fire, and water). At the closure of the terrace a full-story staircase draws one upward onto the dipteral octastyle portico. Throughout this entire processional route, one is surrounded by white Vermont marble with an unusually high mica content. Reflections are so brilliant on sunny days that they almost blind the viewer. White glazed-tile roofs contribute to the luminous quality of the building. The opulence of these materials is complemented by the richness of the architectural and sculptural decoration and the intricacy of its allegorical theme.
Atop the long cheek blocks of the staircase James Earle Fraser's stern seated figures, the Authority of Law (on the south) and the Contemplation of Justice (on the north), guard the temple entrance. Sixteen columns (and eight pilasters) are Gilbert's American variant of the Corinthian order where heraldic eagles are set between splayed volutes. The frieze of braziers hung with garlands (symbolic of the plenty existing in an ordered society) is particularly lavish. In the pediment, Robert Aitken's central sculptural figures represent Liberty Enthroned Guarded by Order and Authority. They are attended by six allegorical figures symbolic of Counsel and Research who were modeled after Americans responsible for bringing the Supreme Court and its quarters into being, although they are all shown in Roman garb. The muscular reclining figures at the edges of the composition are Chief Justice William Howard Taft on the north
The rarely noticed pediment on the east front depicts a related theme, Justice the Guardian of Liberty. Hermon A. MacNeil's central figures are representations of great law givers, Moses, Confucius, and Solon. Their supporting figures are symbolic of the functions of the Supreme Court: Means of Enforcing the Law, Tempering Justice with Mercy, Settlement of Disputes between the States. In a secondary group is Protection of Maritime Rights, Pondering of Judgment, Tribute to this Court, and the Fable of the Tortoise and the Hare. This in-antis Corinthian portico, while less fully developed than the entrance, is symbolically important, as the chief justice's suite of rooms, directly behind it.
The bronze entrance doors and the frieze of the Supreme Court chamber are the two major remaining foci of Gilbert's iconographical program, and they both depict the historical development of law throughout the world. John Donnelly, Jr., modeled the thirteen-ton bronze doors, each with eight panels. On the left the scenes are derived from classical historical and literary sources, the Shield of Achilles (Greek law), Praetor's Edict (Roman law), and the Justinian Code (religious law). The panels on the right illustrate events in Anglo-American legal history: Magna Charta, Westminster Statute, Coke, James I, and Story, Marshall. On both doors, the most remote events are at the bottom, and they move chronologically to the top as they move from laws themselves to their application or enforcement. Hence, like its neighbor the Library of Congress, the Supreme Court places American achievements within the broad continuum of human history.
In canonical Beaux-Arts fashion, the extended experience of approaching and entering the Supreme Court continues inside the building as one moves along the central axis toward the court chamber. Gilbert employed two common Beaux-Arts methods of spatial division along his processional route: changes in level (both modest and dramatic) and screens of columns. The visitor passes through six distinct spaces before arriving at the courtroom. The colonnaded main hall has double rows of columns at each end and an additional screen masking its apsidal termination. The lateral columns standing close to the niched and pilastered side walls create a measured and stately approach to the courtroom. All are Roman Doric in white Georgia marble and carry an entablature whose frieze is composed of classical heads in profile on the model of classical coins, as well as numerous abstract symbols associated with the law. Busts of justices alternate with the columns and are set within the niches. The space is emphatically trabeated with the flat, coffered ceiling of painted plaster (red, white, and blue) made possible by the use of a steel frame.
The courtroom cannot be experienced as Gilbert intended, for he planned it to be brightly lit from side windows that are now covered with heavy curtains. The light was to be filtered through two sets of double Ionic columns, one set within the courtroom and the second across intervening halls that separate it from courtyards on either side. Gilbert may have had in mind Leon Battista Alberti's dictum from his De re aedificatoria (c. 1450) that the place where justice is dispensed should be flooded with light, a metaphorical statement. The Supreme Court chamber is a near cube with the top third composed of an attic story with four marble friezes in low relief sculpted by Adolph A. Weinman after pencil sketches by Gilbert. Above the justices' bench is the Majesty of Law and opposite it the Power of Government. On the west wall is Justice and Divine Inspiration. On both sides are portraits of the world's law givers, including Confucius, Augustus, and Napoleon. John Marshall is the only American represented. Costly and sumptuous materials were used throughout, including colored marble from Africa and Europe. Bronze screens with repetitive small-scale Roman ornaments are set between the side columns and cast intricate shadows on the interior surfaces when the curtains are drawn.
The office wings are raised on a walled podium. E-shaped, they are attached to the sides of the temple, creating four internal courtyards. These are highly developed architectural spaces with Corinthian columns or pilasters on all four facades as they are viewed