Thomas is a young Irish immigrant who fled the famine and relies on his resourcefulness to survive in mid-19th century America. He joins the army alongside his closest companion, John Cole, to secure steady, albeit dangerous, employment. Finding profound joy and a sense of authentic identity when wearing women's clothing, Thomas embraces a fluid gender expression whenever societal constraints allow. His deep affection for his chosen family anchors him through the brutalities of the American Indian Wars and the Civil War.

John is a New England orphan of unknown Native American heritage who partners with Thomas to survive poverty. He proves to be a steady, handsome, and pragmatic companion who readily steps into the role of a devoted partner and father. Serving alongside Thomas in the military, John endures the overt prejudice of his fellow soldiers while maintaining a quiet, protective demeanor.

Tilson Neale serves as the commanding officer for Thomas and John's company during the American Indian Wars and the Civil War. He attempts to uphold a personal sense of justice and morality, insisting that Native Americans possess souls and should be treated accordingly. His high-minded ideals frequently clash with the brutal realities of the military campaigns he leads and the violent prejudices of his men.

Winona is an Oglala Sioux child who becomes the center of Thomas and John's lives after they adopt her from a military fort. She possesses a bright, observant nature and embraces her new family dynamic with easy acceptance. Her presence inspires Thomas and John to seek domestic stability and prioritize her education and safety above their own.

Caught-His-Horse-First is an Oglala Sioux leader whose initial interactions with the American army involve profound generosity. He leads his people through severe famine and shifting treaty boundaries as white emigrants increasingly encroach on their lands. His attempts to protect his community's territory place him in direct opposition to the United States military forces.

Starling is a hardened soldier who fights alongside Thomas and John on the Great Plains and in the Civil War. He harbors virulent prejudices against almost all non-white and non-American groups, frequently voicing his racist opinions without filter. Despite his hostile worldview, he forms a strange, enduring bond with Thomas and remains intensely loyal to Major Neale.

Lige is a Tennessee-born sharpshooter who befriends Thomas and John during their military service. He possesses a practical mindset and proves to be a reliable companion during both mundane fort life and intense combat. He maintains his Union loyalties during the Civil War, a stance that isolates him from his Confederate-sympathizing neighbors back home.

Sergeant Wellington is a crude, aggressive military officer who commands Thomas and John during their early years in the army. He frequently expresses intense hatred for Native Americans, the Irish, and other minority groups, using his authority to enact cruelty whenever possible. His brutal disposition contrasts sharply with Major Neale's attempts at discipline.

Titus Noone is a pragmatic businessman who runs a saloon in Daggsville, Missouri. He provides Thomas and John with their first opportunity to perform in women's clothing, recognizing the financial potential of providing the local miners with the illusion of female company. He later operates a minstrel troupe in Michigan.

Watchorn is a young, talkative soldier in Thomas's early military company. He participates enthusiastically in the brutal actions of the military campaigns in California, committing horrific crimes during a raid on a Yurok village.

Pearl is a soldier in Major Neale's company who partakes in the massacre of the Yurok people. His participation in wartime atrocities prompts Major Neale to detain him, demonstrating the limits and applications of military justice on the frontier.

Mrs. Neale is the polite and compassionate wife of Major Neale. She brings a gentler presence to the rough military fort, establishing a school for the children born to soldiers and Native women. Thomas admires her refined feminine wardrobe and closely observes her mannerisms.

Caleb is a soldier who survives a devastating ambush by pretending to be dead in the grass. After recovering from a bullet wound through his cheek, he earns a reputation for immense luck and becomes a popular participant in the soldiers' regular card games.

Nathan is an early friend to Thomas and John in the military. His sudden death in a skirmish deeply saddens the two men, who honor him by placing a poisonous purple flower on his grave.

Beulah McSweny is a free Black man who befriends Thomas, John, and Winona in Michigan. As a literate man whose father secured his freedom, he offers to tutor Winona when local schools refuse to admit a Native American child. He also serves as the family's landlord and encourages the men's Union sympathies.

FitzGerald is a fellow Irish immigrant who lost his family to famine and traveled to the United States through Quebec. He joins the Union army and brings encouragement and morale to new recruits, participating enthusiastically in camp theatricals.

Rosalee is a Black woman living with Lige Magan on his tobacco farm in Tennessee. She creates a warm, welcoming home environment, frequently joining the others in singing and dancing during the evenings. She completely accepts Thomas's presentation in women's clothing without judgment.

Tennyson is a Black man who helps Lige Magan work the tobacco farm in Tennessee. He immediately respects Thomas's gender presentation, respectfully addressing Thomas as a woman upon their first meeting. He helps defend the farm from local attackers.

Tach Petrie is a former Confederate soldier who operates as a violent marauder and orchestrates local lynchings in post-war Tennessee. He resents Lige Magan's Union loyalties and leads armed assaults against the tobacco farm.

Captain Sowell is a military officer who attempts to oppose unjust orders on the Great Plains. He tries to be a voice of morality within a corrupt system, formally reporting misconduct when superior officers order the slaughter of non-combatants.

Sarjohn is a German translator who works alongside the American military during encounters with Native American tribes on the Great Plains. He plays a role in formal military proceedings when disputes arise.

Corporal Poulson is a soldier tasked with tracking down Thomas for a bureaucratic error involving military commission papers. He proves sympathetic, preferring to avoid executing a former comrade if given a plausible excuse.

Captain Sexton is a military officer tasked with presiding over a court-martial trial. He approaches his duties with a strict adherence to protocol, halting proceedings when testimony reveals complex layers of misconduct among the ranks.

Henryson is a miner leader in northern California who uses racist generalizations and accusations of theft to justify murdering the local Yurok population. He supplies the arriving soldiers with alcohol to encourage their participation in the slaughter.

Birdsong is a Shawnee boy who aids the soldiers by guiding them to a massive herd of buffalo. He skillfully hunts alongside Thomas, communicating effectively through sign language to coordinate their efforts.

Mr. Graham serves as an interpreter for the American army during tense negotiations with the Sioux. He is tasked with bridging the communication gap during fraught standoffs on the plains.

Bert Calhoun is a Black Union soldier who survives a massacre only to be sent to a brutal Confederate prisoner-of-war camp. He suffers from a severe hand injury and is denied medical treatment due to the racist policies of his captors.

Private Kidd is a fellow Union prisoner of war at Andersonville. He understands the lethal dynamics of the camp and warns Thomas against showing public sympathy for the injured Black soldiers, knowing it will invite deadly retaliation from the guards.

Lieutenant Sprague is a Confederate soldier stationed at the Andersonville prison camp. He cruelly taunts the starving Union prisoners about their bleak prospects for exchange, even while suffering from severe food shortages himself.

Carthage Daly is a Black prisoner of war held by the Confederates. Because the guards refuse to provide him with rations based on his race, he relies entirely on the secret generosity of John Cole to survive the brutal conditions.

Joe is a Shawnee man who uses an assumed English name to pass safely among white travelers. He shares a pleasant evening with the family and feels a nostalgic connection to Winona, though he expresses fatalistic views about the future of Native Americans.