Sir Daniel Day-Lewis met his wife Rebecca Miller, the daughter of Arthur Miller, while shooting the film.
Sir Daniel Day-Lewis didn't bathe or shower from the time filming began to when it wrapped, in order to stay in character.
Sir Daniel Day-Lewis built the house he lived in as John Proctor, because of his habit of maintaining his character through the entire duration of the filming.
Though based on historical events, Arthur Miller altered some events to more strongly parallel his own experience during the McCarthy era. In particular, Abigail Williams was only 12. Miller made her older so that she could have had a sexual relationship with John Proctor. This paralleled Miller's own adulterous relationship with Marilyn Monroe.
Playwright Arthur Miller got his inspiration for "The Crucible" during the Hollywood black-listings. It reminded him of the paranoia, the finger-pointing and the all around outrageousness that the Salem Witch Hunt had possessed. Miller himself was called before The House of Representatives' Committee on Un-American Activities in 1956 to testify against his friends and, like his character John Proctor, refused to implicate them.