The Manor (Glen Cove Mansion)

Charles Pratt, an oil pioneer and the founder of Pratt Institute, began assembling nearly 1,100 acres at Dosoris, in Glen Cove, in the 1880s, and by about 1905 several of his children had built houses near the shore. The Manor was built for his son John Teele Pratt, an oil executive, and John's wife, Ruth Baker Pratt. It was completed in 1910 on a 55-acre estate. The architect was Charles Adams Platt (1861 to 1933), who designed a brick Georgian Revival house with a two-story portico at the entrance and a double staircase inside. Country Life magazine named it one of the best 12 country houses in America.

The house was a center of family and social life for the Pratts. John Teele Pratt lived there until his death in 1927. Ruth Baker Pratt went on to a political career, and in 1929 she was elected to Congress as a Republican, the first woman from New York to serve there. She sat in the 71st and 72nd Congresses and kept the estate until her death in 1965.

After her death the Harrison Conference Center bought the house from the Pratt family, and in 1967 it opened as one of the first conference center hotels in the United States. It was known as Harrison House until 1985, when it took the name Glen Cove Mansion Hotel and Conference Center. A restoration and renovation in 2019 produced The Mansion at Glen Cove, the name it uses today. The hotel's own pages give conflicting dates for the Harrison House name. They also say that during Herbert Hoover's presidency a Pratt estate served as a summer White House, without naming which estate; that claim was not confirmed by an independent source in this research.

The house has appeared in many films and television series. The hotel's list includes Sabrina (1995), The Americans, The Blacklist, Madam Secretary and Succession.

Today the house is a hotel, conference center and wedding venue on 55 acres at 200 Dosoris Lane. Visitors can see the interior by staying overnight, dining or attending an event; no public history tour schedule was found. The domain glencovemansion.com, which the hotel still uses for its email address, now serves an unrelated organization's website and should not be linked. Several other Pratt family houses survive nearby, including Welwyn, the home of John's brother Harold I. Pratt, which is now a Holocaust museum in a county preserve.