Templeton (White Eagle)

Alfred I. du Pont had worked for many years in his family's gunpowder company in Delaware, rising to vice president of operations, before a family dispute led him to resign and start an import and export firm in New York. He and his wife Alicia, a daughter of Judge Edward Bradford, planned to move from Nemours, their Delaware house by Carrère and Hastings, to Long Island's North Shore. Du Pont acquired about 250 acres in the Westbury area and in 1916 commissioned Thomas Hastings to design a summer house there.

The house, called White Eagle, was completed in 1918. NYIT puts its cost at $1.1 million. It is a red brick Georgian Revival house of about 41,000 square feet with limestone and marble trim, a recessive wing, and an elliptical colonnade on the east front that frames views toward a fifteen-acre natural pond. Charles of London designed the interiors. Alicia du Pont died during construction, and du Pont never lived in the finished house. He remarried in 1921, returned to Nemours and later moved his business to Florida, where he died in 1935.

The estate then passed to Captain Frederick E. Guest and his wife Amy Phipps Guest. Guest was a British politician, a grandson of the seventh Duke of Marlborough and a first cousin of Winston Churchill. Amy Guest was a daughter of Henry Phipps Jr., Andrew Carnegie's partner in Carnegie Steel, and she backed Amelia Earhart's 1928 Atlantic flight. The National Register nomination says the Guests moved in during 1923; NYIT dates their purchase to 1926. They renamed the house Templeton and, under Hastings's supervision, added windows, a glass garden room and a garage. Mrs. Guest also brought in a white marble stair hall from her parents' New York City house. She lived at Templeton until her death in 1959, and her son Winston Guest, a well-known polo player, inherited it.

In 1972 New York Institute of Technology bought the mansion from the Guest family and named it for Alexander P. de Seversky, the Russian-born aviator and NYIT trustee who helped arrange the purchase. NYIT turned the bedrooms into offices and the garage into classrooms, and in the early 2000s sold fifty-six acres of the surrounding land for houses. About 44 acres remain with the mansion, which lies technically in the Village of Brookville although it sits on NYIT's Old Westbury campus. It was listed on the National Register of Historic Places in 2009. Visitors can see the house by booking an event through the NYIT de Seversky Mansion.