Seaman House, 1923. In 1851, two brothers (sons of early 19th-century medical innovator Dr. Valentine Seaman) purchased a hillside property near the top of Manhattan and began to erect a substantial summer home constructed with locally-quarried white marble. The resulting house was a grand 30-room Italianate villa with a gatehouse at the bottom of the hill. The gatehouse was, in fact, a massive marble arch that served as the entranceway for the steep driveway that led up to the home. John F. Seaman also constructed greenhouses and sprawling gardens, as he was fond of that pass time. The house was willed to a relative, Lawrence Drake, following the death of John's widow in 1878. While the widow spread her wealth out between 36 heirs, most of the other heirs believed that Lawrence had "unduly influenced" a senile old woman. The heirs sued the man but lost the suit. Less than 20 years later Lawrence sold the property to the Suburban Riding and Driving Club. The membership of the club was the crème de la crème of New York society, and the mansion served as its opulent clubhouse. In 1905 the estate was sold to a construction developer who lived in the home and used the gateway arch as his office. The land was sold once again in 1938, and the large mansion and outbuildings were razed for a new apartment complex. The arch still stands at 5065 Broadway, having been boxed in by an auto body shop decades ago. It lost its roof to a fire in the 1970s and has seen many better days but is hidden right there in plain sight.

In 1851, two brothers (sons of early 19th-century medical innovator Dr. Valentine Seaman) purchased a hillside property near the top of Manhattan and began to erect a substantial summer home constructed with locally-quarried white marble.