Monroeville, Ala., resident Harper Lee filed the lawsuit Friday in federal court in Manhattan. She seeks unspecified damages from a son-in-law of her former literary agent and related entities.
Lee says the relative failed to properly protect the copyright after the agent who had represented her since the book was published in 1960 became ill a decade ago. The 87-year-old author says he took advantage of her declining hearing and eyesight seven years ago to get her to assign the book's copyright to him.
The former agent's son-in-law hasn't returned a call seeking comment.
"To Kill a Mockingbird" won the Pulitzer for fiction and is widely assigned in schools. The film version won three Academy Awards.