Homer is a twelve-year-old orphan from Pine Swamp, Maine, who possesses a vivid imagination and a habit of telling tall tales to impress adults. Fiercely loyal, he begins a dangerous journey across Civil War-era America to track down the Union army and rescue his drafted brother. He is resourceful and determined, frequently relying on his wits and his ability to lie convincingly to escape perilous situations.

Harold is Homer's seventeen-year-old brother. He serves as the younger boy's primary protector after their parents die. Despite being underage for military service, he is illegally forced into the Union army when their uncle lies about his age to a corrupt magistrate. He is brave, responsible, and shoulders the heavy burden of keeping himself and his brother safe in a hostile world.

Squinton, commonly known as Squint, is the cruel uncle of Homer and Harold. He resents the burden of caring for his orphaned nephews. He works them relentlessly, starves them, and locks them in a moldy root cellar at night. He illegally sells Harold into the Union army draft to pocket a profit from a wealthy man avoiding service.

The charismatic manager of the Caravan of Miracles, a traveling circus and medicine show. Dressed in polished boots and a coat with gold-piece buttons, he is a smooth-talking showman who entertains Union troops and sells them a patent medicine that is secretly just whiskey. He rescues Homer from a difficult situation and offers him a place in the show as "The Amazing Pig Boy."

A wealthy, deeply religious Quaker who owns a tourmaline mine in Maine. Tall and black-clad with a flowing white beard, he strictly adheres to his pacifist beliefs. He is a prominent conductor on the Underground Railroad, using his estate and wealth to hide escaping enslaved people on their way to Canada.

A grimy, one-eyed bounty hunter who smells overpoweringly of rot. He roams the Northern woods to search for runaway enslaved people, intending to capture them and return them South for cash rewards. He is ruthless, cruel, and eager to resort to physical violence.

A nearly toothless bounty hunter who works alongside Stink Mullins. Smaller and more cunning than his partner, he acts as the brains of their illicit operation. He forces Homer into wearing a rope leash and acting as a spy to locate a hidden Underground Railroad station.

A courageous, free-born Black man from Rhode Island who operates as a conductor on the Underground Railroad. He risks his own freedom and safety to guide runaway enslaved people north. Even when captured and facing death, he maintains a defiant and dignified moral stance.

A skinny, red-haired performer in Professor Fleabottom's Caravan of Miracles, whose real name is Minerva. She presents a tough exterior but acts as a surrogate mother to Homer. She ensures he bathes, eats candy, and stays relatively safe within the rough-and-tumble circus environment.

The plump, gray-haired cook at the Brewster estate. She is warm, generous, and immediately takes to Homer despite his tendency to spin wild lies. She feeds him nourishing meals, including stacks of pancakes, and offers him much-needed maternal affection.

The historical commander of the Twentieth Maine Infantry Regiment. He leads his men during critical moments of battle at Gettysburg. He holds strict but fair authority over his soldiers, balancing military discipline with a sense of honor and compassion.

A tall, skinny, and nervous young clergyman. Mr. Brewster entrusts him to escort Homer safely to New York. Though a prize-winning Bible student, he is highly gullible and easily distracted by the prospect of high society and romance, making him a poor guardian.

A beautiful, well-dressed young woman who crosses paths with Homer and Mr. Willow at the Portland harbor. She uses her charm and flirtatious behavior to quickly captivate the inexperienced clergyman, pulling his attention away from his responsibilities to Homer.

A well-dressed man claiming to be a lawyer, who accompanies his sister Kate. He acts overly accommodating and smoothly inserts himself into Mr. Willow and Homer's travel plans, raising Homer's immediate suspicions with his slick demeanor.

A bearded gymnast and member of the Talented Tumbling Brillo Brothers in the Caravan of Miracles. He juggles, performs physical stunts, and acts as a driver for the circus wagons, forming an informal family unit with Homer during the boy's time with the show.

The other half of the Talented Tumbling Brillo Brothers act. Alongside his gymnastics duties, he serves as the camp cook, making delicious meals of sausage and biscuits that quickly win Homer's loyalty.

A local whiskey seller in Pine Swamp, Maine, commonly known as Corny. He is a heavy drinker who eagerly assists Squinton Leach in tracking down the runaway Figg brothers, participating in their capture and Harold's forced conscription for a small payout.