Interesting. I thought that the first serial killer was in Chicago during the World’s Fair, as detailed in “Devil in the White City”.
Me too.
That’s why this article caught my attention.
HHH wasn’t the first but he was certainly prolific.
L
Connection to Little House on the Prairie
The Ingalls family, made famous in the books and television series Little House on the Prairie, lived near Independence, and Laura Ingalls Wilder mentioned the Bender family in her writing and speeches. In 1937 she gave a speech at a book fair, which was later transcribed and printed in the September 1978 Saturday Evening Post, and in the 1988 bookA Little House Sampler. She mentioned stopping at the Inn, as well as recounting the rumors of the murders spreading through their community. She alleged that her father "Pa Ingalls" joined in a vigilante hunt for the killers, and when he spoke of later searches for them she recalled, "At such times Pa always said in a strange tone of finality, 'They will never be found.' They were never found and later I formed my own conclusions why."[18][19] Some have cast doubt on the story saying that Laura would have been only 4 when her family moved away from the area, and that the Benders were exposed in 1873, two years after the Ingallses left.[20]
Actually, The Harpe brothers were one of the first in the US
https://en.wikipedia.org/wiki/Harpe_brothers
What about Vlad Tepes (1431-1477, aka the Impaler, or Count Drakoola)?
Of course, he had the power of the state behind him. So, to be fair, if officially sanctioned, even democratically elected, serial murderers are to get due credit, looking at the 20th century, you'd have to include the wide mustache (Dzhugashvili) and the narrow mustache (Schicklgruber). Between them, they put all other serial murderers in the shade!