Pan American Union Building

	Pan American Union Building
	U.S. National Register of Historic Places
	U.S. National Historic Landmark
	Organization of American States headquarters building, with the Statue of Isabella I in front (2015)
Location	17th Street NW between C Street NW and Constitution Avenue, NW.; Washington, D.C.
Coordinates	38°53′34″N 77°02′25″W / 38.89288°N 77.04026°W
Built	1908–1910
Architect	Paul P. Cret and Albert Kelsey
NRHP reference No.	69000298, 10000625
Significant dates
Added to NRHP	4 June 1969
Designated NHL	13 January 2021

The Pan American Union Building is the headquarters for the Organization of American States. It is located at 17th Street N.W. between C Street N.W. and Constitution Avenue, Northwest, Washington, D.C.^[1]

History

On the former site of the John Peter Van Ness Mansion. The cornerstone was laid on May 11, 1908, by Theodore Roosevelt, Elihu Root, and Andrew Carnegie^[2] (who largely financed the building's construction), and the building was dedicated on April 26, 1910.^[3]

In 1919, the initial meeting of the International Labour Organization was held in the building.^[4]

Between 1921 and 1922, the building was used for committee and subcommittee hearings throughout the Washington Naval Conference while closely guarded by marines with fixed bayonets. ^[5]

The building was added to the National Register of Historic Places in 1969, and was designated a National Historic Landmark in 2021, for its architecture and its role in international diplomacy.