why would miller include the note on historical accuracy?

Miller wants his audience to know exactly how much of his play is based on truth and how much of it is fiction. On the one hand, he wants to state up front that for dramatic purposes his characters are not people who actually lived; he points out that "many characters (are) fused into one, the number of girls involved in the 'crying-out' has been reduced", and several judges are "symbolized...in Hathorne and Danforth". This reduces confusion, and frees him from the liability of misrepresenting the lives of the real people upon whose experiences the play is based. On the other hand, Miller also wants his reader to know that he did strive to remain truthful in recounting "the essential nature of one of the strangest and most awful chapters in human history". Miller wrote the play during the McCarthy era of the 1940s, a time of intolerance and hysteria, as a warning about what actually did happen during another time in history when intolerance and hysteria were allowed to get tragically far out of hand. He wants his audience to know that although he has taken liberties in depicting his characters, the situations and events he recounts did indeed happen as he describes. Miller clearly wants his audience to take his message seriously.