Developed chriefly between 1928 and 1938 under the direction of Secretary of the Treasury Andrew Mellon's "Mellon Board," the buildings that comprise the Federal Triangle Historic District are a visible symbol of the growth taking place in the U.S. federal government at the beginning of the 20th century.
The oldest of the buildings in Federal Triangle, the Old Post Office, was constructed between 1891 and 1899 and was followed by the neoclassical Beaux Arts-style District Building, constructed between 1904 and 1908.
The Mellon Board's neoclassical ensemble consists of nine enormous federal buildings constructed around a series of outdoor plazas and inner courts. It is this country's most imposing example of the monumental civic center concept, popular among city planners in the early decades of the 20th century.
DC Inventory: March 7, 1968 (Joint Committee on Landmarks)
Within the Pennsylvania Avenue National Historic Site