W. B. Thompson Mansion

About

The W. B. Thompson Mansion, also known as Alder Manor, is a historic home located on North Broadway (U.S. Route 9) in the Greystone section of Yonkers, New York, United States. It is an early 20th-century mansion designed by Carrère and Hastings in the Renaissance Revival architectural style. In 1982, it was listed on the National Register of Historic Places.

It was built by William Boyce Thompson, a mining tycoon and financier, as his weekend home. At the turn of the century, large riverside estates characterized much of Yonkers; today the Thompson Mansion is one of the few to have survived the city's 20th-century urbanization. The Thompson family lived there until the mid-20th century; afterwards it was willed to the Roman Catholic Archdiocese of New York and became Mary Elizabeth Seton High School, the first Catholic school in Yonkers.