H.H. Holmes was one of the first documented serial killers, before the term was even used.
H.H. Holmes' real name was Herman Webster Mudgett. Holmes used various aliases all the time to commit scams and con women to collect their life insurance and beneficiarie, throughout his life being married to four different women at the same time. The last three were never legal from never actually having been legally separated from his prior spouse/ victim.
HH Holmes grew up in New Hampshire (USA), which is where his appetite for killing manifested at an early age. He moved to various states, scamming people, companies, morgues, etc., but he's most famous for his hotel in Chicago, which he designed specifically for torture, murder and body disposal. The hotel contained trapdoors, secret passageways, gas chambers, industrial sized furnaces (to cremate bodies and mitigate capture). A US post office was built on that property, and the postal service is reluctant to let anyone investigate and search for bodies, info/clues, etc.
According to Martin Scorsese during an interview with Cinema Blend, he had to stop taking meetings on the script's development for six months while working on his film, Silence (2016). Scorsese concluded by stating, that meetings for the script's continuing development will recommence in January 2017.
Leonardo DiCaprio purchased the film rights to the book in 2010; the movie was to be produced by Paramount Pictures, Stacey Sher and Michael Shamberg's Double Feature Films, and DiCaprio's own production company Appian Way Productions. Hulu took over and the project was turned into a television series in 2019.