- Creighton Brown: A British boy who gets in trouble with the law and who hates the American rebels. Hoping to cure him of his bad behavior, Creighton's mother sends him to the Colonies to live with his uncle. He is captured with Uncle Gower and Hale during the trip to the Colonies, but is released when he poses as an indentured servant. Creighton is then ordered to spy on his captors by Gower. He later gives himself up to Franklin by telling him his role in the escape of Col. Gower and Lt. Hale. He becomes Franklin's assistant in the print shop alongside Sophie. In the beginning of the book, Creighton is an arrogant Englishman who thought his only purpose in life was to play card games. In his adventures in the Colonies, he becomes aware of the many things in life besides games and ale. He faces challenges to figure out where his loyalties should lie.
- Benjamin Franklin: American Patriot who publishes The Liberty Tree, a banned rebel newspaper. Franklin takes Creighton in because he believes him to be loyal to the Patriots. He dies after a fire in the print shop which was started by British soldiers. The soldiers, under Gower's orders, dressed as Native Americans and then set fire to the print shop.
- Benedict Arnold: American general who befriends Creighton. Arnold is a fighting man who favors violence over peaceful resolutions. He has a very bad temper and enjoys dueling. His leg was amputated in a battle. 
- Peter: A giant who is in the rebel army and is a year older than Creighton. Because of his size, he is sometimes clumsy. Peter's character is based on Peter Francisco, a private in the American army during the Revolution who was sixteen and stood six and a third feet tall.
- Sophie: A French housemaid who works for Franklin. Sophie's family was killed by British soldiers, so she despises most British people. Sophie cares for Creighton when he gets sick or hurt. She and Creighton have a flirty relationship but do not openly show affection to one another. She also works in Franklin's print shop.
- Colonel Gower: Creighton's Uncle. Gower is a cruel and a disagreeable man who is made the Lieutenant Governor of West Florida. He invades French Haiti and succeeds in capturing it. He also supervises the execution of George Washington at the end of the story.
- Lieutenant Harvey Hale: A British Royal Marine officer who is instructed to escort Creighton to America. The two become friends. Hale is imprisoned with Gower. They eventually escape and Hale becomes Gower's assistant.
- Harry Brown: Creighton's father who is jailed for warning American colonists about a forthcoming British-ordered Native American assault, but Creighton rescues him.
- General George Washington: The American General in the Revolutionary War.
The whole book is a historical fiction.