W. B. Thompson Mansion

W. B. Thompson Mansion
U.S. National Register of Historic Places
East elevation, 2009
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Location	Yonkers, New York
Coordinates	40°58′22″N 73°53′4″W / 40.97278°N 73.88444°W / 40.97278; -73.88444
Area	1.5 acres (0.61 ha)
Built	1912[2]
Architect	Carrere & Hastings
Architectural style	Renaissance Revival
NRHP reference No.	82001277[1]
Added to NRHP	October 29, 1982

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.^[1]

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.

After ten years as a high school, it was upgraded to a junior college. A few years after merging with Iona College, the campus was closed. While the other buildings on the property were repurposed, the mansion fell into neglect and was looted until Tara Circle, an Irish American cultural organization, bought it from the city. To raise money for its restoration, Tara Circle holds occasional events there and rents it out for weddings and filming for movies such as Mona Lisa Smile^[3] and A Beautiful Mind.^[4]