As her name suggests, Mary Rambo is both Mary, the saintly mother of Jesus, and Aunt Jemima, the female version of Sambo. Mary is a strong black woman who has learned to survive the violence and corruption of the city by relying on her inner resources. A Southern woman who now lives in the North, Mary provides the narrator's only source of love and comfort.
After his harrowing experience at the Liberty Paint Factory Hospital, the narrator is grateful for Mary's kindness and generosity. Seeing him simply as a fellow human being who needs help, Mary takes him into her home, cooks for him, and nurses him back to health. When he can't pay his rent, she tells him not to worry. Seeing how depressed he is about his situation, Mary encourages him and reassures him that he will make something of himself and be "a credit to his race." She does everything she can to demonstrate her faith in him and, in effect, adopts him as her surrogate son.
During this time, the narrator sees Mary as the saintly mother figure, referring to her as his anchor and guide, and appreciating her support and generosity. But after he meets Brother Jack and begins to work for the Brotherhood, he sees Mary through different eyes. She becomes a source of shame and embarrassment for him, prompting him to try to shatter her image, as symbolized by his futile attempt to discard the cast-iron bank. The bank, like Mary, represents a part of his heritage he wants to forget. Although he initially appreciates her cooking, he now complains of his steady diet of cabbage. At first he sees her home as a sanctuary and source of solace and comfort, but later he notices the noise, poverty, and filth surrounding her, as indicated by the banging on the pipes, the smell of cabbage, and the invasion of roaches.
He finally leaves Mary without even saying goodbye, confident that she will survive, having undoubtedly gone through similar experiences with other black men.
Mary is a survivor who represents the courage and dignity of the black woman. Although she is not based on any specific historical character, she is a woman in the tradition of Harriet Tubman, Sojourner Truth, or Mary McCloud Bethune.