Though the topic is somewhat debated, America's first serial killer is largely regarded as Herman Webster Mudgette, better known as Dr. Henry Howard or "H.H." Holmes. Born to a devout Methodist farming family in New Hampshire, his childhood was quite normal — aside from the fact that his favorite hobby was dissecting animals, of course. After completing high school at the age of 16 Holmes went on to teach school, married Clara Lovering and fathered a child with her. Soon Holmes set his sights on higher education. After a short stint at another university Holmes attended the University of Michigan and studied medicine and surgery.
While in Medical school Holmes used his access to cadavers to scam insurance companies by stealing bodies and passing them off as people he had insured who had died accidentally. After graduating from medical school H.H. Holmes abandoned his wife and child, had several different jobs and continued running scams. In 1887 Holmes got married again — this time to Myrta Belknap. This marriage was entered into without divorcing his first wife, making Holmes a bigamist in addition to being a bloodthirsty psychopath. The couple had a daughter named Lucy before Holmes left to marry a third woman named Georgiana Yoke, thus giving him three simultaneous wives.
In August of 1886 Holmes arrived in Chicago sans any of his wives or children. He quickly got a job at a drugstore and eventually ended up purchasing it. It is generally accepted that the owner of the drugstore met a nefarious end at the hands of H.H. Holmes as she seemingly disappeared, and anytime anyone questioned Holmes about her whereabouts he simply said she was with family in California. After purchasing the drugstore Holmes then bought a large lot across the street and started construction on what would eventually come to be referred to as the "Murder Castle," but was formally called "The World's Fair Hotel."
The ground floor of the expansive building was comprised of the new location of Holmes' drugstore and several other shops. The second and third floors were a twisting, confusing maze of windowless rooms that only locked from the outside and staircases that led to nowhere. There were also a variety of chutes, trapdoors, and dumbwaiters that lead to the basement — the place where the real horror was. During the construction of the massive building Holmes would frequently hire and fire builders. He would say they were incompetent, but really Holmes just didn't want anyone else to know the exact layout of his building.
H.H. Holmes murdered his victims, who were mostly female employees, women he dated, and hotel guests, in many different ways. Some of them were locked in windowless, soundproof rooms Holmes had run gas lines to. He would then turn on the gas and watch through a peep hole as the people were asphyxiated. H.H. also had a room called "the secret hanging room," which was a pretty self-explanatory location where he murdered his prey via hanging. He even had a room that was only accessible by a trapdoor and had no exit. He would put people inside and then leave them to slowly die of starvation and dehydration.
Once his victims had perished H.H. Holmes went to the basement to dispose of the bodies. The basement contained an acid vat, a crematory, and lime pits. Holmes would then frequently dissect the bodies, remove the flesh, and sell the skeletons to medical schools. Some other methods he would employ to get rid of the bodies included dissolving them in acid, cremating them in the furnace, or burying them in the lime pits. In addition to the many different methods of disposal the basement offered, it also contained instruments of torture like a stretching rack.
When the World's Fair ended the economy was terrible so Holmes moved around the United States and Canada for several years. In 1894 a tip led to Holmes being arrested for a horse scam. After questioning some of H.H. Holmes' former employees and searching his property he was charged with murder. Although only nine murders were confirmed, there could have been between 20 and 200 victims of Holmes' savagery. When he was first questioned H.H. confessed to 100 murders, but later would only cop to 27. The many means of body disposal Holmes had available to him makes it impossible to know an exact number of those who were killed, or the timeline in which they were murdered.
When his case went to trial there was enough evidence to land H.H. Holmes a sentence of death by hanging. In May of 1896, America's first serial killer met his end at the gallows, where his neck failed to break. Holmes then suffered for 15-20 minutes — suffocating slowly like many of his helpless victims.