Legendary gangster Jack Diamond is the novel's protagonist and a kind of Irish- American hero like Finn McCool and Jesse James. Finn McCool is a legendary hero of Old Ireland, a huge giant of mythological proportions. Jack, one of the most famous men in America, also has a larger-than-life image that he often says is exaggerated. Jack is compared to Jesse James, the famous outlaw and American legend. Both Jack and Jesse James employ lawless violence to accomplish their ends. Jack grew up in a poor Irish-American family in Philadelphia, and was raised to be a devout Catholic. Much of Jack's own internal struggle with his corrupt lifestyle stems from Catholic guilt. Whenever Jack is harassed by the press and after he starts getting into legal trouble, he persistently claims that his disreputable image is a fabrication of the press and that he's really not such a bad person. Marcus states that his favorite stories about Jack are usually the lies and tall tales. A good portion of this book consists of anecdotes people have told Marcus over the years—stories that may or may not be true. At the beginning of the novel, Tipper, Flossie, and Marcus all disagree about the manner in which Jack was killed. Legs partly weaves an American legend that combines the true story of Jack Diamond's life with rumors and stories about his existence. The novel is narrated forty-five years after the events it describes took place, and this distance emphasizes Jack's position as mythical hero of a bygone era.