Hetty, commonly called Handful, is a sharp and observant enslaved girl in the Grimké household in early 1800s Charleston. Assigned to serve Sarah as a personal maid, she possesses a keen mind and an independent spirit nurtured by her mother's storytelling and survival lessons. She faces the violent realities of enslavement but holds onto the knowledge of her own humanity, secretly learning to read with Sarah's help.

Sarah is the highly intelligent daughter of a wealthy Charleston judge. Traumatized by witnessing violence against an enslaved woman at age four, she develops a stutter and a profound hatred of slavery. She desires to become a lawyer like her brothers, frequently reading from her father's extensive library, but struggles against the restrictive expectations placed on Southern women of her class.

Charlotte, known to her daughter as Mauma, is an expert seamstress enslaved by the Grimké family. She possesses a fiercely rebellious streak and secretly resists her enslavement through subtle acts of defiance, such as ruining sleeves or breaking dishes. She strives to pass down her heritage to her children by creating a story quilt that records their family history.

Angelina, called Nina, is the bold and beautiful youngest daughter of the Grimké household. Raised largely by her older sister Sarah, she adopts a fierce, uncompromising stance against slavery from a young age. She possesses a naturally daring personality, completely rejecting societal expectations to become a traditional Charleston belle.

Mary, known as Missus, is the strict and uncompromising matriarch of the Grimké family. She oversees the household with rigid authority and enforces an elaborate social code upon both her children and the people she enslaves. She relies on swift, cruel physical punishments to maintain order and control over the estate.

Judge John Grimké is the wealthy patriarch of the Grimké family and a judge on South Carolina's highest court. He possesses an extensive law library that his daughter Sarah covets. He strictly enforces traditional gender roles, ultimately crushing Sarah's dreams of a legal profession to ensure she conforms to society's expectations.

Denmark is a free Black man living in Charleston who passionately advocates for the liberation of all enslaved people. He is a prominent speaker at the African Methodist Episcopal church and actively organizes resistance efforts. His uncompromising stance challenges the deeply entrenched systems of the city.

Israel is a devout Quaker living outside Philadelphia who introduces Sarah to the principles of Quakerism. He strongly opposes slavery and lives a life guided by his egalitarian religious convictions. He provides Sarah with literature and emotional support as she questions her place in Southern society.

Thomas is one of Sarah's brothers. He receives the formal education and legal training that Sarah is denied due to her gender, though he occasionally shares his studies with her before she is permanently banned from their father's library.

Goodis is an enslaved gardener working on the Grimké estate. He observes the daily events of the household from the yard and maintains a quiet, steady presence amidst the family's frequent turmoil.

Lucretia is a Quaker minister and abolitionist living in Philadelphia. She offers crucial guidance to those seeking to align their faith with anti-slavery action and models a life of public religious leadership for women.

Burke is a young man in Charleston society who begins courting Sarah. He represents the traditional path of marriage and domesticity expected of young women of Sarah's social standing.

Theodore is a member of the American Anti-Slavery Society who works to train public speakers. He assists the Grimké sisters in refining their public addresses, though he eventually asks them to conform to gender norms by restricting their audiences.

Sky is a young enslaved girl who possesses a remarkable talent for gardening. She is deeply protective of her family and actively participates in their quiet rebellions against the harsh conditions of their lives, transforming an overgrown yard into a thriving space.

Rosetta is an enslaved woman in the Grimké household. The violence she suffers serves as a formative trauma for young Sarah, forever altering the child's worldview and solidifying her lifelong hatred of slavery.