Alice Walker's The Color Purple weaves an intricate mosaic of women joined by their love for each other, the men who abuse them, and the children they care for.
In the first few letters, Celie tells God that she has been raped by her father and that she is pregnant for the second time with his child. Celie's mother is quite ill and after cursing Celie, dies, leaving Celie alone to face her father. Celie then turns her attention to protecting her sister, Nettie, from her father's sexual advances. Celie soon marries Mr. _______ (later called Albert) after her father strikes a bargain with the older widower, and Celie finds herself in a loveless marriage, caring for her husband's four children and being regularly raped and beaten. Celie becomes fixated on Shug Avery, a glamorous blues singer who is her husband's mistress. Several years later, Celie eagerly accepts the responsibility of nursing Shug back to health, thus beginning a lifetime of friendship and love between the two women.
The oldest of Celie's stepchildren, Harpo, marries an independent young women, Sofia, and soon after, Celie encourages Harpo to beat her into submission, just as all men have beaten Celie. Sofia later confronts Celie about this betrayal, but that confrontation leads to a deep and enduring sisterhood, and Sofia remains an independent, strong woman throughout the novel. The two women create a "Sister's Choice" quilt together—the symbolism of quilts permeates much of the novel. Just as scraps of cloth come together to form a new, strong, useful product, so, too, can black women come together to forge a similar strong and useful bond.
Sofia later punches the town's white mayor, an act that lands her in prison and snatches the independence she so values. By this time, she and Harpo have split up and taken other lovers, so the women in Sofia's life take on the responsibility of releasing her from jail. An alliance forms between Celie, Shug, Sofia's sisters, and Squeak, Harpo's mistress. When trying to help Sofia, Squeak is raped by her uncle, the prison warden, but in telling her friends about the rape, she becomes stronger, insisting that she will no longer be called by her nickname and beginning to compose her own blues music. Sofia is able to leave prison, but she finds herself caged nonetheless, working as a maid in a white household.
Meanwhile, Nettie has become a missionary in Africa and has written countless letters to Celie, all of which Albert has hidden. Nettie, in spite of her upbringing, is a self-confident, strong, faith-filled woman. When Celie discovers Nettie's letters, she not only catches up on her sister's life, she also discovers that her own two children are alive and living with a missionary couple with whom Nettie works. Nettie's letters about their shared African heritage are a tonic to Celie, who becomes stronger and more self-assured every day. That confidence soon turns to fury—over her rapes, her beatings, and the love and affection the men in her life have kept from her. Nettie's letters also demonstrate parallels between Celie's world and the African world, including the bond that can develop among the multiple wives of African men, the deep friendship and love that exists between two women, the deep love of a man for a woman, and the unrelenting structure of sex roles.
With her new-found strength, Celie confronts her father, whom she has just learned is her stepfather and not a blood relative, and this brings great relief to Celie, who now know that her children are not her brother and sister. She also confronts Albert, leaves him, and moves to Memphis to live with Shug, a move that stuns and pains Albert. In Memphis, Celie, who started wearing pants when she gained her strength and self-confidence, opens a business as a pantsmaker. Later, after Shug has taken on a male lover, Celie visits Albert, and they develop a new bond that eventually grows into love and respect.
Nettie, still living in Africa, marries the now-widowed man who had adopted her sister's children, thus becoming a mother to her niece and nephew. Later, when Celie's father dies, she and Nettie inherit his home, creating financial freedom for the two women. At the novel's end, the two sisters are reunited, while Albert and Harpo have learned to take on new roles in the household and in their relationships.
Note that the novel's title is alluded to in Letter 12, when Celie associates the color purple with royalty and longs for a purple dress. But the title undoubtedly comes from a passage near the end of the novel, in which Shug says that she believes that it "pisses God off if you walk by the color purple in a field somewhere and don't notice it."