Nat is put in the stocks because he violates the strict standards of behavior by being rowdy (in itself “illegal”); by playing with the pagan jack-o-lanterns, which to the Puritans signified evil; and lastly by insulting an important person in town, William Ashby. He does this because he is offended by what seems to be Kit’s plans to marry William, but there are important dramatic purposes to “why Nat is put in the stocks.” It offers another indication of the harshness of the Puritan community; it foreshadows Kit’s predicament later when she is accused of witchcraft; it links Nat with Kit, showing them to be “soul-mates” in their rebellious and playful spirits; and it shows the kindness and courage of Kit, who dares approach him, again risking the disapproval of the community in doing so.
Nat was put in the stocks because he was one of the sailors who put Jack-o-lanterns in the home of William Ashby. It was just a joke, but Ashby was probably chosen because Nat was upset that he was going to marry Kit. Ashby did not see the incident as a joke. He saw it as satanic. This is hard for us to understand, but All Hallows Eve was considered by many Puritans to be a satanic holiday and anything associated with it to be satanic. Some Christians today are still offended by jack-o-lanterns and other halloween celebrations.