Stella is a biracial woman living in a Creole cottage in New Orleans. As a mistress to Mason Frye, she endures a restricted and oppressive life that strips her of her autonomy. She possesses a talent for embroidery, which she uses to secretly stitch maps to help enslaved men escape. She relies heavily on her older sister, Ammanee, but steadily discovers her own capacity for resistance and bravery.

William is a Black enslaved man with an extraordinary talent for playing the flute. He escapes his enslaver, Mason Frye, to join the 3rd Louisiana Native Guard. Despite facing severe discrimination and harsh treatment within the Union Army, William utilizes his musical skills to connect with others, maintain his humanity, and survive the brutal realities of war.

Ammanee is Stella's older sister who serves as a maid in the Burgundy Street cottage. Her dark skin tone places her in a more vulnerable social position than her sister and mother. She acts as a fierce protector for her younger sister, often taking on daunting tasks to shield Stella from harm. Ammanee harbors hopes for a future with the man she loves, though her options remain heavily restricted by the racist systems of the South.

Jacob Kling is an American Jewish man of German descent serving in a Union infantry band. A talented cornet player, he encounters antisemitic prejudice from his fellow white soldiers. He finds a profound sense of belonging and camaraderie with William. The two men bond over their shared musical talents and mutual feelings of being outsiders in a discriminatory society.

Lily Kling is Jacob's wife, a wealthy Jewish New Yorker and an outspoken abolitionist. She leverages her privilege to support the Union cause, organizing quilting bees to make bandages and raising funds alongside prominent activists. She maintains a constant correspondence with Jacob, offering a Northern perspective on the war effort while fighting for intersectional equality.

Samuel Kling is Jacob's brother who lives on a luxurious plantation in Satartia, Mississippi. He runs a successful department store and aligns himself with the Confederacy, primarily out of economic self-interest to protect his privileged lifestyle. His political stance creates a deep ideological rift between him and his brother.

Mason Frye is a staunch Confederate supporter and a quartermaster in the Confederate Army. He exerts oppressive control over Stella and Ammanee in the Burgundy Street cottage. Frye views the enslaved people he claims to own as tools for his own gratification, treating them with casual cruelty and viewing their lives as entirely transactional.

Janie is Stella and Ammanee's mother, a formerly enslaved woman who endured years of trauma at the hands of her enslaver, Percy. Though she has attained manumission, her traumatic past leads her to encourage a pessimistic, self-preservationist outlook in her daughters. She advises them to keep their heads down and avoid dreaming of an unattainable freedom.

Percy is a wealthy white plantation owner and Stella's biological father. He granted Janie manumission but continues to control her life, mandating that she remain on Rampart Street where he can monitor her and exert authority over her family. He acts as the architect of his daughters' constrained lives.

Teddy is a 10-year-old drummer boy in the 3rd Louisiana Native Guard. Born free in New Orleans, he fled to the army camp after a group of white men murdered his parents. Traumatized and mostly silent, Teddy communicates through the rhythms of his drum, finding a mentor and protector in William.

Arthur Kahn is a German Jewish immigrant and Lily's father. He runs a large music supply shop in New York City and worries constantly for his daughter's safety, encouraging her to move back home amidst the growing unrest in the city.

Ernestine Rose is a prominent Jewish abolitionist and suffragette based in New York. She serves as a hero and friend to Lily, inspiring her activism and refusing to be silenced by the men who jeer at her speeches.

Clinton Righter is a violent plantation owner in Georgia who previously enslaved William. He inflicted brutal punishments on his enslaved workers and harbored deep resentment toward William's family, punishing them severely for seeking freedom.

Eleanor Righter is Clinton Righter's wife. Recognizing William's prodigious musical talent, she covertly arranged for him to learn classical music and how to read sheet music from her own instructor, keeping the lessons a secret from her husband.

Tilly is William's mother, a woman who possessed a powerful singing voice on the Righter plantation. She demonstrated immense bravery by sacrificing her own safety to help William's father escape to the North, subsequently suffering a brutal punishment that left her unable to speak.

Isaiah is William's father, an enslaved man who successfully fled the Righter plantation. His memory serves as a guiding and comforting presence for William during his lowest moments.

Benjamin is an enslaved blacksmith who grew up alongside Ammanee on Percy's plantation. He remains bound to his enslaver's property but shares a deep, clandestine affection with Ammanee, occasionally meeting her in secret under the guise of running errands.

Eliza Baum is Samuel Kling's wife. She staunchly defends her family's use of enslaved labor, prioritizing her economic and social standing over moral opposition to enslavement. Her perspective creates a massive ideological divide between her and her sister-in-law, Lily.

Miss Hyacinth is a neighbor from Rampart Street who contacts Stella for assistance. Desperate to save her son from Confederate conscription, she provides Stella with the necessary supplies to begin embroidering secret escape maps.

Miss Emilienne is a resident of Rampart Street who serves as the community's de facto midwife. She relies on Stella's mapping skills to aid her family and provides essential medical support to the women in her neighborhood.

Miss Claudette is a pragmatic woman living on Rampart Street who believes self-sufficiency is the key to survival. She initially hesitates to involve herself in political resistance due to the high risks involved, preferring to protect herself.

Kati is Jacob and Samuel's mother, a Bavarian immigrant who instilled a love of music in her sons. Her memory provides Jacob with emotional grounding during his service in the Union Army.

James is Teddy's father, a free Black man who owned a successful tobacco shop in New Orleans before being violently murdered by a racist mob during a home invasion.

Phebe is Teddy's mother. During the brutal attack on their home, she manages to hide her son under the bed, sacrificing her life to ensure he survives the invasion.