10. The Second Mrs. Astor’s House, 840 Fifth Avenue: Demolished
When Caroline Astor’s nephew William Astor knocked down his own townhouse to build the original Waldorf Hotel, right next door to her own mansion, she up and left. In 1894, Caroline and her son headed uptown to a more fashionable spot on 65th Street and Fifth Avenue. “Starchitect” Richard Morris Hunt, the same man who designed other Gilded Age 5th Avenue mansions like William K. and Alva Vanderbilt’s Petit Chateau, was hired to design Caroline’s new abode. While the exterior appeared to be that of one large mansion, the interior was actually split into two separate living spaces, one for Caroline, and one for her son John Jacob Astor. The two residences were connected by a ballroom that could hold 1,200 guests (the same amount of guests that Alva Vanderbilt had invited to her fancy dress ball).
After Caroline’s death, John Jacob Astor took over his mother’s portion of the mansion and made some major renovations. Unfortunately, he wouldn’t live long enough to enjoy the new space. After honeymooning in Europe with his new second wife, he booked a return trip aboard the doomed RMS Titanic. John did not survive the tragedy. While his new wife and her maid did make it safely back to New York City, they were forced to give up the mansion, as dictated by Astor’s will. It passed to Astor’s son from his first marriage, William Vincent Astor. Preferring his estate out on Long Island, William sold the 65th Street property to developers and auctioned off the interiors. Today the Temple Emanu-El stands in its place.