The Benjamin N. Duke House, also called the Duke–Semans Mansion and the Benjamin N. and Sarah Duke House, is a landmarked mansion located at 1009 Fifth Avenue at East 82nd Street in the Upper East Side of Manhattan, New York City. It was built in 1899-1901 and was designed by the firm of Welch, Smith & Provot in the Beaux-Arts style. History The house was built speculatively by developers William W. Hall and Thomas M. Hall, and not for a specific owner. Shortly after the mansion was completed in 1901, it was bought by Benjamin N. Duke, a tobacco, textile and energy industrialist and philanthropist, who was chairman of the American Tobacco Company at that time. Benjamin's brother, James, another tobacco entrepreneur, bought the house in 1907. He lived there until his own mansion at 1 East 78th Street – now landmarked as the James B. Duke House – was completed in 1912. After James Duke relocated, the mansion became the residence of Benjamin Duke's son, Angier Buchanan Duke, until 1919, when his sister Mary Lillian Duke married A. J. Drexel Biddle Jr., and the couple moved in. Later, their daughter, Mary Semans, took over the residence. Members of the Duke family owned the mansion until 2006, when it was sold for US$40 million to Tamir Sapir, an American real estate mogul. Mexican telecom magnate Carlos Slim, at the time the richest person in the world, bought the mansion in 2010 for US$44 million. In May 2015, Sotheby's marketed the house for $80 million, nearly twice the amount Slim had paid for it; the house became one of the most expensive public listings in New York. Slim canceled the sale in early 2016 after no one expressed interest in buying the house at that time. He placed the house for sale again in January 2023. The Benjamin N. Duke House, which is one of the few remnants of the many similarly luxurious mansions along Fifth Avenue facing Central Park, underwent a restoration in 1985. It was designated a New York City Landmark in 1974, and was added to the National Register of Historic Places in 1989. Description Designed by the firm of Welch, Smith & Provot from 1899 to 1901, the house was built in the Beaux-Arts style with a French Renaissance interior, decorated mainly with Louis XV style furniture. The house is eight stories high, and measures 100 feet