Why does Miller begin with background rather than immediately plunging into action?

Miller was giving us a background into the witchtrials and reminding us of the ferocity with which rumors and accusations fly in the midst of panic. Th background plants the seed..... not so much for Miller's inaccurate portrayal of history, but as a statement to the times. The play is a parable for the McCarthy era, in which similar 'witch hunts' occurred targeting citizens as communists rather than disciples of Satan.