Like his guests, Astor (seen in this 1895 photo) enjoyed a pampered existence as a member of one of New York's most powerful families.
But he was also a keen inventor - creating an early form of air conditioning by blowing cold air over the hotel's wall vents - and an avid bibliophile.
With the help of Thornwillow Press, a small publisher of limited-edition books, the hotel is in the process of restoring and cataloguing the nearly 3,000 books that Astor left behind.
"If John Jacob Astor were to walk through the rooms, it would be entirely familiar to him," said Luke Ives Pontifel, Thornwillow's founder. "He would recognize the books on the shelves. It's a time capsule."