This event was the conviction and execution of residents of the village of Salem, Massachusetts in 1692 on charges of witchcraft.
At that time, the Puritans generally believed that they were in constant battle with Satan.
It all started when 2 girls aged 9 and 11 presented symptoms that the doctors could not explain and so they considered them possessed. These symptoms soon appeared in other girls.
Concerned residents began to suspect a slave woman who knew about witchcraft and who the girls often visited. The girls reported that the slave practiced witchcraft so that she could heal them. They also started naming many other people as being involved.
A total of 100 people were reported. Those who pleaded guilty were spared execution. In addition to hanging, the punishments were stoning and imprisonment.
[Source: en.wikipedia.org]
