Angel is a 16-year-old Black girl living in the prosperous, segregated community of Greenwood. She possesses a deep sense of compassion, frequently helping her neighbors and caring for her dying father. She aligns with Booker T. Washington's philosophies, favoring slow, measured progress for her community. Angel saves her money from braiding hair to purchase crutches for her father and accepts a summer job running a mobile library.

Isaiah is a 16-year-old Black boy who spends his time reading and writing poetry in secret. He lives with his widowed mother and feels frustrated by the slow pace of racial progress, favoring the urgent, active philosophies of W. E. B. Du Bois. Though highly intelligent, Isaiah hides his academic interests to fit in with his mischievous best friend, Muggy. He develops strong romantic feelings for Angel Hill, which prompts him to change his behavior.

Mr. Hill is Angel's father. He suffers from a rapidly progressing illness that prevents him from walking unassisted. Despite his severe physical decline, he remains affectionate and observant, warning his daughter that approaching storm clouds indicate impending trouble for their community.

Mrs. Hill is Angel's mother. She works from home fixing the hair of local children, such as the Barney sisters, to financially support her family while caring for her sick husband. She eventually insists that Angel stop acting as a caretaker and enjoy her youth.

Mrs. Wilson is Isaiah's widowed mother. She has raised him as a single parent since her husband died fighting in World War I. She encourages her son's education but questions his preference for W. E. B. Du Bois's ideas, viewing them as potentially reckless.

Muggy is Isaiah's best friend. He comes from a financially comfortable family but frequently acts out as a bully and prankster. He ridicules Isaiah for his interest in books and often targets Angel for harassment, hiding his own insecurities behind a facade of cruelty.

Miss Ferris is an English teacher at Washington High School. She recognizes Isaiah's talent for writing and hires both him and Angel to operate a summer mobile library. She actively supports her students' intellectual growth, maintaining a diverse personal library that includes works by both Booker T. Washington and W. E. B. Du Bois.

Dorothy Mae is a teenage girl in Greenwood. She briefly dates Isaiah, though he finds her uninterested in intellectual conversations. She quietly harbors deeper ambitions, such as a desire to fly, but usually conforms to the gender expectations placed upon her.

Mrs. Nichelle is Angel's next-door neighbor. She struggles to rest because her newborn baby, Michael, suffers from colic and cries incessantly. She relies heavily on Angel's volunteer help to get any peace.

Vice Principal Anniston is an administrator at Washington High School, the school that Angel and Isaiah attend. He lives next door to the Hill family with his wife and newborn son.

Michael is the newborn son of Mrs. Nichelle and Vice Principal Anniston. He suffers from colic, crying frequently until Angel steps in to walk him and soothe him to sleep.

Truly is a young, joyful girl who attends the same church as Angel. She exhibits a natural giddiness and frequently sings and dances during Sunday services.

Deacon Yancey is an older church member and neighbor. He misses his recently deceased wife and harbors a strict grudge against Isaiah's family due to a past incident where Isaiah's father accused the deacon's son of theft.

Mrs. Tate is a neighborhood woman known for her prized juniper bush. She keeps a close eye on the local teenagers and demands respect when Muggy misbehaves near her property.

Mr. Morris is a retired woodshop owner. He uses his carpentry skills to build a custom wooden crate with distinct compartments for Angel and Isaiah to carry books on their delivery bicycle.

Mrs. Edward is an elderly, hard-of-hearing neighbor. She suffers from arthritis and holds quiet knowledge regarding the local boys who play pranks on her.

Mrs. Arnold is Truly's mother and a member of the Greenwood community. She attends church with her family and serves as a quiet fixture in the neighborhood.