For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Celie is raped by her Pa, gives birth to children that are taken away from her, gets married, and loses Nettie. In every possible way, Celie is a victim.
Act II
Mr.__’s mistress moves in and Celie falls in love with her. She discovers all the letters from Nettie that Mr.__ hid all these decades. Celie finally finds her voice, stands up for herself, and leaves Mr.__.
Act III
Celie starts her own life, indulging her interest in sewing pants and starting a small clothing business. Celie waits for her sister to come home. She learns all about Nettie’s life in Africa and her children, Olivia and Adam. Mr.__ changes and the two of them become friends. Eventually, Shug and Mr.__ become like family. And then, at long last, Nettie comes home—and brings her husband and Celie’s children.