What does Hawthorne gain by including the names of actual persons and places in "Young Goodman Brown"?
Deacon Gookin could be based on Daniel Gookin, a settler of Virginia and Massachusetts and a writer on the topic of American Indians. He held several public offices in the colony, and he was an elected magistrate for thirty-five years. He did, however, undergo a period of diminished popularity as a result of his sympathies with Native Americans, but his good reputation eventually prevailed.
Goody (Martha) Cory, whom Goody Cloyse calls an "unhanged witch," was actually hanged on September 22, 1692 after having been convicted of witchcraft. She was relatively well-respected, and so her accusation and conviction marked a departure from the less-respected social pariahs whom the accusing girls had named before. Cory was outspoken in denouncing the witch trials, and this could be why she was accused.
Martha Carrier, whom the narrator of the story calls a "rampant hag," a woman "who had received the devil's promise to be queen of hell," was a real-life victim of the Salem Witch Trials. In fact, Reverend Cotton Mather used these very same words—"rampant hag" and "Queen of Hell"—to describe her so Hawthorne is certainly drawing on her history here. She, of course, was not guilty of witchcraft, but her magic was blamed for a smallpox epidemic in Andover, a town near Salem, two years before the trials. She was hanged as a witch in Salem on August 19, 1692.
So, then, we have three people who were well-respected in their communities, and two of whom were victims of the witch trials themselves. Perhaps Hawthorne draws on the names of real persons in order to add elements of real life to his stories, making them seem more immediate, relevant, and plausible. Perhaps he does so because these women were really innocent of the crimes of which they were accused and Hawthorne wants to draw attention to the way the Devil might work to accuse innocents, making them suffer for his pleasure or to bring other innocents down with them. In Salem, the fault was with the accusers, not the accused, and it could be that Hawthorne wants to point this out, since the two female victims named in the story were known, by the time he wrote this, to be victims and not perpetrators. Perhaps it is some combination of these reasons.
The colonists are Puritans (a Calvinist-focused version of Christianity). Hawthorne was fascinated by the Puritan legacy, and became very interested in historical accounts of the Salem Witch Trials and the abuse of Quakers after he discovered his ancestors had been involved in both. Hawthorne used historical references (in this case relating to the Salem Witch Trials) to give the piece a more "historical" feel, and also to help support his allegory.
He uses Young Goodman Brown's experience to explore (and in some cases, criticize) particular points of Puritan doctrine, such as predetermination/election (the idea that those who are "elected" to heave are predetermined before birth, as are those meant for hell), and the intolerance that led to the hysteria of the Salem Witch Trials. Using real names and places helps to support this exploration and give the reader the same sort of feeling he had when we began to dig through the historical documents (an example would be Cotton Mather's "Wonders of the Invisible World").
In addition, the inclusion of names such as Young Goodman Brown and Faith provide the readers with clues to how these characters were to be perceived. In some cases, such as Young Goodman Brown's, the name is indicative as to his actual character. In others, such as Faith's and Goody Cloyse's, the names are ironic; while they could be symbolic of the respective faith and goodness of those characters, they are actually the opposite.