what actual historical events did a writer refer to

Are you referring to the introduction in Custom House? The connection between Salem (witch trials) and the Puritans is made early on. Hawthorne's family originally settled in Salem, and he is a direct descendent of several notable ancestors. He describes his ancestors as severe Puritans decked out in black robes, laying harsh judgment upon people who strayed from their faith. When discussing his ancestors, Hawthorne is both reverent and mocking, jokingly wondering how an idler such as himself could have born from such noble lineage.