The Crucible is a study in the mass hysteria which led to the 1692 Salem witchcraft trials, concentrating on the fate of some of the key figures caught up in the persecution. It powerfully depicts people and principles under pressure and the issues and motivations involved. At the same time, it is also a parable for the events of the McCarthy era in the USA of the 1950s when anyone suspected of left-wing views was arraigned for 'Un-American Activities'.