The Reverend Mr. Hooper's preoccupation with secret sin suggests that truly embracing Calvinist theology as Puritans did would lead to a rather grim outlook on life. Research the communities of early American Puritan colonies. Did the members of these Puritan communities constantly remind one another of Original Sin and lead bleak lives of suffering and isolation like Hooper?
Hawthorne calls his short story a parable. In addition to the story of Mr. Moody provided by Hawthorne in the footnote, could Hawthorne have been alluding to biblical mentions of veils? Read Exodus 34:30-33, in which Moses wears a "vail'' to shield his followers from the blinding glory of his face, which radiates as a result of his having been in God's presence for forty days and forty nights. Read also II Corinthians 3:7-18, in which St. Paul explains why Moses really wore the veil. Do these biblical accounts shed any light on Hooper's black veil?
Hawthorne's ancestors were involved in both the persecution of Quakers and the execution of people convicted of witchcraft in Salem, Massachusetts, in 1690. Research either of these events. You may want to read The Crucible by Arthur Miller; The Salem Witch Trials by Earle Rice, Jr.; or Neighbors, Friends, or Madness: The Puritan Adjustment to Quakerism in Seventeenth-Century Massachusetts Bay by Jonathan M. Chu. How did Puritans treat people who were different from them? What similarities are there between Mr. Hooper and others the Puritans disliked?