I am afraid that the eNotes editors are only allowed to answer one question. Additional inquiries must be listed separately as individual postings.
The Crucible by Arthur Miller is allegorical.
First, an allegory is a narrative that works as an long metaphor.
[See this link for an example of an extended metaphor in the epitaph Ben Franklin originally wanted on his gravestone. It compares his life to a book:
Arthur Miller's inspiration for this play came in the guise of the McCarthy hearings in the 1950s. An overwhelming fear of the an insidious influx of communist doctrines, hidden beneath the very fabric of the U.S. society, made people fearful and paranoid: none more than Senator Joseph McCarthy. For a time, he and his House Committee on Un-American Activities wielded the power to lift up or destroy names, reputations and careers by slinging innuendo and half-truths in the name of national security, a threat McCarthy felt came from the U.S. Communist party (a recognized political group) and its members, et al. Many people were targets of McCarthy's "witch hunt," as it was called, especially those involved with film in Hollywood, music in general, other members of the other arts including writers, etc., as well as government workers, union organizers, and even teachers. (Arthur Miller was one of many who came under suspicion.)
Whereas great pieces of fictional literature—such as satire—were written to draw attention to political injustices or ineptitude, as seen in Jonathan Swift's Gulliver's Travels (which is a fantastical account of a giant in the land of tiny people, among other situtations), The Crucible is factually-based on witch trials that took place in this country, where close to 20 people were hung or pressed to death based on the hysterical ravings of mostly pre-adolescent or adolescent girls. An entire adult, religious community was brought to its knees by the lies and play-acting practiced by these girls as they accused one innocent adult after another of bewitching them. Decent people like Goody Nurse and Giles Corey were destroyed by the paranoia of the Puritan religious culture that saw the Devil at every turn.
The practices were paralleled in what is known as McCarthyism, which did much the same thing, except this time, children did not control the madness: Senator McCarthy and his "minions" carried on a twentieth century witch hunt. While no one was put to death, but those put on trial were sometimes black listed, making it impossible for them to work. Some reputations were never repaired. McCarthy and his committee saw communist plots where there were none. The hysterical rantings and ravings of McCarthy and his supporters, lost support when people got tired of the national upheaval, the black listing and investigations. In addition,
Much of the undoing of McCarthyism came at the hands of the Supreme Court.
Ultimately, McCarthyism declined, and the "trials" and the tribulations lost public interest and support.
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