Dr. Henry Howard Holmes was born on May 16, 1861, in New Hampshire, under the name Herman Webster Mudgett. Mudgett married young, had a child, and studied to become a doctor. He also began to run petty insurance scams, his marriage disintegrated, and he abandoned his wife and child, although he never officially divorced. He bounced around the East Coast, leaving several towns over suspicious circumstances.
Mudgett ultimately headed for Chicago in 1886 and, concerned that his previous shady activity might catch up with him, changed his name to Henry Howard Holmes. He got a job at the drugstore of the soon-to-be-widowed Elizabeth Holton. Holmes impressed Holton with his hard work, and when he offered to buy the drugstore from her, she accepted. Holmes was to pay for the pharmacy in installments, but then Elizabeth Holton quickly disappeared. Holmes claimed that she had moved to California. He bought the empty lot across the street and quickly built what he called the "World's Fair Hotel" in anticipation of the Chicago World's Fair of 1893. It was so big, locals dubbed it "The Castle."
The bottom floor of the Castle had space for Holmes's drug store and other retail shops. The upper two floors appeared to be a hotel, but were actually something much more sinister. There he had built doors that could only open from the outside, rooms fitted with gas jets, a vault that could be hermetically sealed, and chutes that lead to a basement laboratory. Holmes began methodically murdering single women who showed up for the World's Fair, a mistress who got pregnant and then demanded marriage, and random individuals in order to collect on their life insurance policies. His mistress's small child was also murdered.
Holmes kept tubs of corrosive acid in his basement to remove the skin of his victims. He then sold the resulting skeletons to medical schools and medical supply companies. Holmes most audacious gambit was luring two wealthy sisters from Texas, swindling them out of property, and murdering both of them - one by locking her in his vault and asphyxiating her with gas, the other most likely by chloroform.
After the fair ended, Chicago experienced a financial slump and Holmes was being being aggressively pursued by numerous creditors. He quickly fled Chicago with a confederate, Benjamin Pitezel, and began a lengthy trek through Texas, St. Louis, Philadelphia, and Toronto. Along the way he would murder Pitezel in an insurance scam, murder three of Pitezel's children, and finally be arrested in November of 1894, in Boston. By then, police in Chicago were thoroughly examining the gruesome remains left behind in the Castle, which included human bones in cellar lime pits, bloody clothing, and scratch marks in the vault, most likely from Holmes's desperate victims.
Although he was connected to the deaths of as many as 200 people, Holmes was hanged in Philadelphia for the murder of Benjamin Pitezel on May 7, 1896.