Harry F. Sinclair House
mansion in Manhattan, New York
The Harry F. Sinclair House (also the Isaac D. Fletcher House or Fletcher–Sinclair Mansion) is a mansion at the southeast corner of East 79th Street and Fifth Avenue on the Upper East Side of Manhattan in New York City, New York, U.S. The house was built between 1897 and 1899. Over the first half of the 20th century, the house was successively the residence of businessmen Isaac D. Fletcher and Harry F. Sinclair, and then the descendants of Peter Stuyvesant, the last Director of New Netherland. The Ukrainian Institute of America acquired the home in 1955, and the institute renovated the building in the 1990s. The house was added to the National Register of Historic Places (NRHP) and was named a National Historic Landmark in 1978.
The mansion was designed in an eclectic French Renaissance style by C. P. H. Gilbert and built by foreman Harvey Murdock. The building largely retains its original design, except for a tankhouse on the roof. Gilbert and Murdock constructed the bulk of the house with brick, which was then faced with limestone ashlar. The northern facade on 79th Street, containing the main entrance, is characterized by multiple windows in square recesses or semi-elliptical and fully Gothic arches. The western facade on Fifth Avenue is symmetrical and dominated by a curved, projecting pavilion. The interior of the mansion comprises 27 rooms on six floors, for a total floor space of 20,000 square feet (1,900 m2).
The public source identifies “Harry F. Sinclair House” as mansion in Manhattan, New York. This brief keeps that definition visible, then builds a research path around Harry, Sinclair and House.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 5, 2026. The linked authority identifier is Q5668753. Authority coordinates are 40.777, -73.964. 3 of 3 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank. The first chronological checks are 1897, 1899, 1955 and 1978.
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This entry incorporates text from “Harry F. Sinclair House” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.