ANational Historic Landmark District may include contributing properties that are buildings, structures, sites or objects, and it may include non-contributing properties. Contributing properties may or may not also be separately listed.
Prior to 1935, efforts to preserve cultural heritage of national importance were made by piecemeal efforts of the United States Congress. In 1935, Congress passed the Historic Sites Act, which authorized the interior secretary authority to formally record and organize historic properties, and to designate properties as having "national historical significance", and gave the National Park Service authority to administer historically significant federally owned properties.[1] Over the following decades, surveys such as the Historic American Buildings Survey amassed information about culturally and architecturally significant properties in a program known as the Historic Sites Survey.[2]
In 1960, the National Park Service took on the administration of the survey data gathered under this legislation, and the National Historic Landmark program began to take more formal shape.[4] When the National Register of Historic Places was established in 1966, the National Historic Landmark program was encompassed within it, and rules and procedures for inclusion and designation were formalized. Because listings (either on the National Register, or as an NHL) often triggered local preservation laws, legislation in 1980 amended the listing procedures to require owner agreement to the designations.[5]
On October 9, 1960, 92 places, properties, or districts were announced as eligible to be designated NHLs by U.S. Secretary of the InteriorFred A. Seaton. Agreements of owners or responsible parties were subsequently obtained, but all 92 have since been considered listed on that 1960 date.[note 1]
The origins of the first National Historic Landmark was a simple cedar post, placed by the Lewis and Clark Expedition on their 1804 outbound trek to the Pacific in commemoration of the death from natural causes of Sergeant Charles Floyd. The cedar plank was later replaced by a 100 ft (30 m) marble obelisk.[6] The Sergeant Floyd MonumentinSioux City, Iowa, was officially designated on June 30, 1960.
More than 2,500 NHLs have been designated. Most, but not all, are in the United States. There are NHLs in all 50 states and the national capital of Washington, D.C. Three states (Pennsylvania, Massachusetts, and New York) account for nearly 25 percent of the nation's NHLs. Three cities within these states, Philadelphia, Boston, and New York City, respectively, all separately have more NHLs than 40 of the 50 states. New York City alone has more NHLs than all but five states: Virginia, California, Pennsylvania, Massachusetts, and New York, the latter of which has the most NHLs of all 50 states. There are 74 NHLs in the District of Columbia.
Approximately half of the National Historic Landmarks are privately owned.[9] The National Historic Landmarks Program relies on suggestions for new designations from the National Park Service, which also assists in maintaining the landmarks. A friends' group of owners and managers, the National Historic Landmark Stewards Association, works to preserve, protect and promote National Historic Landmarks.
If not already listed on the National Register of Historic Places, an NHL is automatically added to the Register upon designation; about three percent of Register listings are NHLs.[10]
^The October 9, 1960, document is included in correspondence with the City of Charleston, South Carolina, whose Charleston Historic District was included in the list, as one of five historic districts named amongst the 92.
The National Archives and Records Administration currently provides at "Charleston Historic District" is very different from a regular National Register of Historic Places (NRHP) or NHL submission; it includes no NRHP or NHL forms at all. It includes correspondence relating to the designation of the Charleston Historic District as an NHL, and correspondence on later threats, further detail on some properties in the district, a nationwide study detailing the places eligible for NHL designation in 1960, a list of these locations, which was conveyed in an October 9, 1960, release from U.S. Secretary of the Interior Fred A. Seaton and includes a nationwide list of sites eligible for inclusion. An outline of themes identified in the National Survey of Historic Sites and Buildings, which the U.S. Department of the Interior was authorized to undertake in 1935 legislation. (Charleston Mayor J. Palmer Gaillard Jr. formally accepted the designation in 1961; three NHL candidate places were named as not having indicated interest to accept the designation. Two letters, in 1966 and 1970, refer to the Charleston Historic District having been designated an NHL in October 1963. However, later NPS documents including this archived 2007 list of NHLs treats the Charleston Historic District and others as having been listed as NHLs on October 9, 1960. Includes correspondence, photos, plans, more. NARA collection of documents associated with Charleston Historic District. National Archives and Records Administration. Archived from the original on May 29, 2022. Retrieved September 8, 2022. 347 pages.
^The counts and locations of NHLs are described most accurately in List of National Historic Landmarks by state. This extends, and corrects errors from, the National Park Service's "National Historic Landmarks Survey List of National Historic Landmarks by State", also referenced.
