It was constructed during the years in 1855 - 1859 in the Gothic Revival style, and was the country residence of Simeon Leland, a wealthy New York City hotel proprietor.

Tall, black-walnut doors ornamented with lion's heads are flanked by slender sidelights crowned with Gothic details.

[2] In 1902, a large wing was built onto the north side adjoining the former billiard room and picture gallery extension followed the Gothic style of the original castle.

During the middle part of the 20th century, the wooden gables, turrets, and crenellations over the bay windows were replaced by galvanized iron copies.

[8] In 1848, Leland purchased a 40-acre site in New Rochelle overlooking Long Island Sound, on land originally developed by New York businessman Norman White as a summer home in 1838.

[11] The castle's new owner, the Manhattan Life Insurance Company, allowed Mrs. Leland and her children to continue living there until 1880.

[2] In 1884, Adrian Iselin, Jr., a member of one of the Hunt Club families from Davenport Neck, purchased the castle and its surrounding acreage for the purpose of developing the land into a residential park.

Uninsured, Miss Morse was forced to leave the castle, and with the promise by Iselin of repairs to the smoke and water damage, it was then purchased by Mother Irene Gill for her Ursuline Seminary.

[8] Today, the residence survives in a suburban area more densely settled than the original grand country estate, and serves as a symbol of the fashion, taste, and lifestyle that Americans idealized in the latter part of the 19th century.