TUSCALOOSA (AP) — U.S. Attorney General Eric Holder says Harper Lee’s famous novel about racial injustice in the South, “To Kill a Mockingbird,” has helped define and improve American life for a half-century.

Holder was at the University of Alabama on Tuesday for a ceremony marking the 50th anniversary of Lee’s only published book. He says the novel remains a powerful teaching tool all these years later.

Lee, who is from the south Alabama town of Monroeville, wasn’t in attendance. She attended law school at Alabama in the 1940s.

The university is establishing a new honor called the Harper Lee Prize of Legal Literature for fictional books about lawyers. It will be given to works that show the positive effects attorneys can have on society.