The Luxe - fact or fiction?

i just read the luxe by anna godbersen and its based on nyc high society in 1899. its sort of like gossip girl for the 1800s and at the start of each chapter it has supposed clippings from diaries of the characters and gossip columnists from newspapers back then. Are those clippings real? Were the characters real people? Are any of the stories accurate, or is this just historical fiction? Because also on the back theres a quote reviewing it from the gossip girl author and she mentions "historically accurate details"..