The Pennsylvania Avenue National Historic Site flanks the broad diagonal of Pennsylvania Avenue between the White House and the Capitol, comprising a large portion of the federal and local governmental cores, as well as part of the City of Washington's Old Downtown. Contained within its irregular bounds is a rich selection of building types and styles, statues, memorials, and parks. In addition, the area features many prominent elements that date from Pierre Charles L'Enfant's 1891 plan for the City of Washington, as amplified in 1901-02 by the McMillan Commission (Senate Park Commission). The National Historic Site provides the urban setting for such naturally recognized features as the Treasury Building, the buildings of Federal Triangle, Ford's Theater, the Old Patent Office, and the buildings centered around Judiciary Square. In addition, the National Historic Site is also home to many lesser-known but historically significant residential and commercial buildings, statues and memorials, and numerous parks and landscape features. It includes approximately 160 contributing buildings c. 1791‑1930.
Natio;nal Historic Site designation and National Register listing October 15, 1966
DC designation: June 19, 1973
National Register listing amended with documentation: October 12, 2007