?! Do the guides really say this? It was built in the Gilded 90s (to replace an incomparably less grand but prettier Tudor style mansion that burned) and in fact it declined into near free fall during the Depression.
Alice Claypoole Gwynne Vanderbilt, widow of Cornelius II, built the mansion and continued to occupy the place seasonally until her death at 89 in 1934 (the reason she lived until 1934 was because her ex-sister-in-law Alva lived until 1933). Alice outlived most of her seven children but when she died her estate was scattered to the surviving kids and several grandchildren and even though it was lopsided (Cornelius III getting the most) it split an already schisming fortune PLUS inheritance and income taxes started to take a toll and by a few years after her death none of her heirs could afford the upkeep on a 70 room beach palace. Same thing happened with most of the white elephants built by the robber baron heirs all over the country; Biltmore in fact had long been closed by the time Alice died, but then baby brother George Washington Vanderbilt II had been sucking hind teat (only inherited $12 million compared to the $80 million each his two oldest brothers got- third brother Fred inherited the same amount but actually died the richest member of the family.)
There’s a great book to be written to whoever has the time to research it on the challenging of the Commodore’s will. It’s got everything: the largest fortune in U.S. history, con-men, spiritualists, a horny old man and a free-love presidential candidate, two bitches from Bama circling each other (the Commodore’s second wife and Alva) waiting for the inheritance, etc..