In the first two weeks of September 1944, the small manufacturing city of Mattoon, Illinois, believed it was being stalked by a “mad gasser” — a prowler who crept to people’s windows after dark and sprayed a sweet-smelling, paralyzing gas into their bedrooms. Beginning with a report on the night of 31 August and exploding after the local Daily Journal-Gazette ran the story of Aline Kearney as a “first victim” on 2 September, roughly two to three dozen residents told police they had been gassed, reporting a strange odor followed by nausea, dryness of the mouth, and temporary weakness or paralysis of the legs. Armed patrols and state investigators combed the city. They found no gas, no chemical, and no gasser.
The outcome was settled within weeks and has not been seriously disputed since. No attacker was ever identified, arrested, or shown to exist; no one suffered any lasting injury; and no device or substance capable of producing the reported attacks was ever located. By 12 and 13 September the police chief, C. Eugene Cole, and the city’s commissioner of public health were publicly attributing the episode to imagination and overwrought nerves, and the supposed gassings, which had peaked sharply, stopped almost as abruptly as they began. The case entered the scientific literature the following year as a model of collective delusion.
This dossier treats the “gasser” as what the evidence shows: not a criminal but a panic. In 1945 the social psychologist Donald M. Johnson published “The ‘Phantom Anesthetist’ of Mattoon: A Field Study of Mass Hysteria” in the Journal of Abnormal and Social Psychology, tracing how an anxious wartime town, primed by a sensational newspaper, converted ordinary smells and ordinary ailments into a coordinated assault by an invisible enemy. The interest is in the mechanism. Sincere, frightened people genuinely felt their symptoms; the symptoms were real and the attacker was not, and a single suggestive headline supplied the script that an entire community then performed.
For roughly two weeks in November 1938, the West Yorkshire mill town of Halifax believed a razor-wielding maniac was loose in its streets, slashing women and the occasional man under cover of darkness. The scare began on 16 November, when two local women, Mary Gledhill and Gertrude Watts, said they had been attacked by a mysterious man with a mallet and “bright buckles” on his shoes; further reports of a phantom with a knife or razor followed, the press christened him the “Halifax Slasher,” and by the last week of the month the town was in the grip of panic. Vigilante mobs patrolled the streets, business all but stopped, and several innocent men, mistaken for the attacker, were beaten by frightened crowds.
The outcome is documented and unambiguous: there was no slasher. On the evening of 29 November, one of the supposed victims, Percy Waddington, admitted that he had inflicted his own wounds. Others quickly confessed the same, and Scotland Yard, which had been called in to assist the overwhelmed local police, concluded that the attacks had been either self-inflicted or imagined. Of the reported victims, all but a few acknowledged that no assailant existed. The scare collapsed within days of the first confession; the local press soon declared it over.
This dossier treats the Halifax Slasher as what the evidence established within a fortnight: not a criminal but a contagion. The wounds were real and so was the terror, but the attacker was a fiction assembled out of newspaper reports, nervous suggestion, and the strange pull of a town-wide drama in which to be a victim was to be, briefly, the center of attention. Five people were ultimately charged with public mischief and four were sent to prison. The interest lies in the mechanism: how an entire town came to hunt, and to fear, a man who had never existed, and how the same newspapers that built him helped take him apart.
In the first decade of the twentieth century, the United States convinced itself that a vast, organized conspiracy — most often imagined as run by foreigners — was abducting innocent young white women off the streets, drugging them, and forcing them into prostitution by the tens of thousands. The fear, known as the “white slavery” panic, peaked between roughly 1907 and 1914. It filled newspapers, pamphlets, lurid books, stage plays, and eventually films; it produced vice commissions in dozens of cities; and on 25 June 1910 it produced a federal law, the White-Slave Traffic Act — the Mann Act — signed by President William Howard Taft and named for its sponsor, Representative James Robert Mann of Illinois, which made it a felony to transport a woman across state lines for prostitution or “any other immoral purpose.”
The outcome is established by the historical record. The sensational version of the threat — a coordinated, immigrant-controlled syndicate kidnapping respectable women into sexual slavery — did not exist. Prostitution was real and widespread, but the investigations meant to prove the conspiracy instead disproved it. A 1910 federal grand jury in New York convened with John D. Rockefeller Jr. as foreman found no evidence of any organized white-slave traffic; city vice commissions, including Chicago’s influential 1911 report, documented extensive prostitution that was overwhelmingly local, commercially disorganized, and entered into for economic reasons rather than by abduction. Historians since have estimated that genuine coercion accounted for only a small fraction of cases — on one widely cited reckoning, well under ten percent.
This dossier treats the panic as a closed case: a moral panic whose factual core was tiny and whose cultural force was enormous. It subsided as a fever within a few years, discredited by its own commissions and overtaken by the First World War. But it left durable residue — a federal law that long outlived the fear that created it, and that was repeatedly turned to purposes its authors never named, most notoriously the 1913 prosecution of the Black heavyweight champion Jack Johnson for his relationships with white women.