What architectural style does the US Supreme Court building imitate?

Cass Gilbert, architect of the US Supreme Court Building, designed the building in the Neoclassical Roman style. The sixteen marble columns supporting the pediment are in the classic Corinthian style.

The pediment itself is decorated with allegorical figures depicting the history of law, and includes the likenesses of Chief Justice Taft and his successor, as well as the architect, sculptor and other people involved in the building's creation. The architrave above the bronze front doors is inscribed with the Words, "Equal Justice Under Law." On the complementary rear architrave are the Words, "Justice the Guardian of Liberty."

On either side of the majestic front steps are two large sculptures by James Earle Fraser. On the left is the seated figure of a woman, representing "Contemplation of Justice"; on the right is the seated figure of a man, representing "Authority (or Guardian) of Law."

William Howard Taft convinced Congress to allocate funds for the Court's construction in 1929, and construction was begun in 1932. Taft and Gilbert both died before the project was completed. Taft passed away in 1930, and was succeeded by Chief Justice Hughes. Cass Gilbert died in 1934, the year before his masterpiece was completed. Gilbert's son, Cass Gilbert, Jr., and other members of his firm completed the project in 1935.