The alternate allegory of Washington's death
This novel offers the opposite of George Washington's real legacy. Because the Americans won in real life, this hypothetical alternative is largely forgotten, so Blackwood includes it as an alternative allegory. What if Britain won, and the Americans were treated as traitors of a throne they felt no loyalty toward? Then it would be a horrific nightmare and Britain's imperial reign would continue.
Benedict Arnold as the type for betrayal
When Creighton betrays his family, that makes him one kind of traitor, but when Arnold defies his loyalties to America, the novel suggests that ultimately his motives were nefarious, whereas Creighton is just a rebellious, disenfranchised adolescent. Benedict Arnold is an archetype for betrayal, because in the novel, his character not only betrays the "good guys," he does it literally for the worst reason—for violence's sake.
Sophie as the anima
Sophie is an archetypal character too. For example, she is the supreme student, constantly devoting time and practice to becoming a more philosophically grounded, ethical person. That makes Creighton do the same things in order to approach her romantically. Her personality points to an obvious flaw in his life—he is wayward because he doesn't have the patience to consider wisdom. Sophie is Greek for "wisdom" and that's exactly what Creighton has to learn from her.
Benjamin Franklin as a symbolic character
Franklin isn't precisely historical in this novel, but from the fictional, imaginative version of Franklin that the novel offers, the reader can see thematic aspects of his character. For instance, from Sophie, we learn that Franklin's approach to life is worthy of consideration. His approach to life is open-minded, but not hypothetical. He is practical, but sometimes he is mystical in his pragmatic approach to life. Sophie finds that he represents a kind of intuitive wisdom.
The motif of terror
When Creighton and his uncle are arrested with their travel companion, Hale, they are terrified, but after they escape, the Brits go back to their plotting. Creighton does not, however. He spies on the Americans and overhears their discussion and is persuaded to betray Britain to join their movement, but he must overcome serious terror in order to tell them the truth. When the Brits win in this alternative history, that is terrifying for the characters in the most extreme way imaginable—it leads to political executions.
