This beautifully scaled and finely detailed building, with exceptionally fine interiors, is a tour de force of restrained neo-classical design and an outstanding example of American civil architecture. Built in two stages from 1839 to 1866, the building is the work of Robert Mills and Thomas U. Walter, two of the most noted 19th-century American architects. The design of the building, based on a traditional Renaissance palazzo, is the first use of the Italianate style for an important public building in America; it also was the first use of marble for one of Washington’s public buildings. Both Mills and his contemporaries considered the building his masterwork.
The southern section of the General Post Office stands on the site of the Samuel Blodgett’s Great Hotel, the first large building in downtown, built in 1795 and purchased by the government in 1810 to house the Post Office Department, City Post Office, and Patent Office. In 1814, Blodgett’s Hotel was the only government building in Washington left unburned by the British, and it became the Hall of Congress for a short period thereafter. Blodgett’s burned to the ground in 1836. By 1839, construction was started on the south section of the present building, designed by Robert Mills for use as the Post Office Department and City Post Office. These offices moved into the building about 1844, but quickly outgrew their space limitations, and in 1855, construction was begun on the north extension designed by Thomas U. Walter. Apparently, consulting engineer Montgomery Meigs suspended construction of the north wing in 1861, and the building was not completed until 1866. During the War, the basement was used as a Union supply depot.
The Post Office Department and City Post Office occupied the building during this entire period, and it was from here that Postmaster General Montgomery Blair initiated home delivery in 1863. Other notable Postmasters General who greatly modernized the postal system were Joseph Holt, Horatio King, and John Wanamaker.
In 1897, upon completion of the new Post Office building on Pennsylvania Avenue (see Old Post Office), Congress transferred the building to the Secretary of the Interior. After this transfer, it housed the General Land Office and the Bureau of Education. One of the government’s first central power, heating and lighting plants, located in the basement, served the Pension Office, the Patent Office, Court House, Court of Appeals, and Bureau of Mines. Interior Department occupancy continued until 1917, when its new offices were completed at 18th and F Streets (see Interior Department Offices). After U.S. entry into World War I, the Army operated the National Selective Service Board from the building, and in 1919, General John J. Pershing occupied the building while preparing his final reports as Commander-in-Chief of the American Expeditionary Forces. After Pershing’s departure in 1921, the Tariff Commission first occupied part of the building, and from 1940 until about 1990 it occupied most of the structure.
Although built in sections, the exterior is a harmonious composition, articulated by Corinthian pilasters and columns, with only minor differences in detail. The Mills wing is of New York marble, and the Walter section of Maryland marble. The keystone above the 8th Street carriageway entrance displays a carved female head representing Fidelity, and bas-reliefs in the spandrels of winged figures bearing a thunderbird and locomotive, symbolizing Electricity and Steam, respectively. These were sculpted by Guido Butti in 1856. Outstanding interior features in the Mills wing are the groined and barrel-vaulted corridors with plaster friezes on the main floor, two graceful curved cantilevered granite stairways in domed alcoves, and the vaulted third floor main hall with a domed central skylight. In the Walter section, the structural system of cast iron beams supporting segmental brick vaults is characteristic, and the wrought iron roof trusses are among the earliest documented examples of rolled I-beam construction. The granite pavilion that housed Walter’s mail receiving room remains in the central courtyard, but his original two-story dead letter office, the major architectural space of the north wing, is only partially preserved.
DC listing: November 8, 1964
National Register listing: March 24, 1969
National Historic Landmark designation: November 11, 1971