Events in New York City in late February led to fatal rumors that a conspiracy of black slaves and white indentured servants was planning to overthrow the city government. At the time, New York was a city of ten thousand people, one-fifth of whom were slaves and black freedmen. A series of fires as well as thefts of silverware had put New Yorkers on edge by the time the governor’s house burned down on March 18. The lieutenant governor publicly blamed workmen who’d been repairing roof gutters, but this explanation was forgotten as soon as Peter Warren’s West Village mansion burned a week later, followed by the home of a Dutchman known for whipping one of his slaves to death. Pipe embers were cited in the latter blaze, but the rash of fires did not stop.

A sixteen-year-old maidservant named Mary Burton gave the panic a kind of legitimacy when she told a neighbor she thought her master, John Hughson, was keeping merchandise stolen by blacks in his tavern cellar. She was arrested for complicity in the alleged crimes and quickly produced a string of names that lengthened over the coming months. She singled out slaves she remembered from her master’s tavern, in addition to her master’s wife and a prostitute named Peggy Carey. Two of the men she mentioned, slaves known only as Quack and Cuffee, were condemned to death and confessed at the last moment, implicating seven more black suspects. Confronted by a mob, the sheriff went ahead and burned the two on the spot. Eventually six of the seven they had named were executed; the seventh was spared for “telling the truth,” which netted fourteen more slave suspects. The confessions grew exponentially until, by the end of August, 154 slaves and freedmen had been imprisoned, 18 executed by hanging, 14 burned alive, and 71 banished. In addition, 24 white New Yorkers were jailed, and 4 of them, including 2 women, were hanged.

The last to die was John Ury, a former priest. After he was hanged, on August 29, more prominent citizens began to come under suspicion, and the absurdity of the theory gradually became evident. Before it ended, however, Mary Burton received one hundred pounds for her testimony. New Yorkers set aside a day in September for thanksgiving that “the delusion” had passed, a delusion that had cost even more lives than the better-remembered Salem witch trials.