When Harper Lee wrote To Kill A Mockingbird, she could not have known it would be hailed as a classic, much less that it would shape the way her hometown viewed its past.

Lee's novel has put Monroeville, Alabama, on the map and acted as a magnet for tourists. It has also stimulated debate in the town about the legacy of racial segregation that prevailed in the south until the 1960s.

Mockingbird tells the story of two children growing up in a fictional southern town similar to Monroeville. Their father, an attorney, is selected to defend a black man accused of raping a white woman. Though the man is innocent, he is convicted by an all-white jury. Some of the book's most powerful moments come as the children realise their father was fighting a doomed cause.

Published in 1960, it was an instant sensation. It won the Pulitzer Prize, has sold at least 30 million copies and a film of it starring Gregory Peck is hailed as a classic.

But sales only tell part of the story. US readers often cite it as their favourite novel. It ranked second only to the Bible in a reader survey of books that had affected them the most. Library Journal voted it the novel of the 20th century.

Every spring, thousands of Mockingbird tourists flock to Monroeville to visit locations associated with Lee's life, the book and the courthouse used in the film.

Trial experience

They also come to watch a stage adaptation of Mockingbird. Act One takes place in the grounds of the court but for Act Two the audience and players move indoors to the original oval-shaped courthouse where the book and film are set.

That setting allows the drama to unfold with audience, judge, lawyers and defendant occupying positions as they would have held in a real trial. Black cast members are even confined to the gallery as they were under segregation.

For the audience, part of the fascination is being witness to injustice. For the volunteer actors, the annual productions have also allowed them to reflect on the book's message. "It's taught me you don't judge people," said Robert Champion, a detective with the Monroeville police who plays Boo Radley, a reclusive figure in the novel who turns out to be a hero.

"One of the lessons is that we should be tolerant of other people but intolerant of injustice," said Champion, who prepared for the role by speaking with people who knew the real-life person on whom the character in the book is based.

Lee may have based her story on an actual rape trial that took place in Monroeville's old courtroom, according to Jane Ellen Clark of the Monroeville County Heritage Museum.

In 1934, Walter Lett, a black man, was tried for the rape of a white woman. He was sentenced to death but according to records recently uncovered, white citizens wrote anonymously to Alabama's governor to say he had been falsely accused.

Lett's sentence was commuted to life in prison and he died of tuberculosis in 1937 in a state prison, Clark said. George Thomas Jones, a former businessman who writes local history, went to school with Lee and remembers her as a tomboy similar to the character of Scout, the novel's narrator.

Outcasts

Jones, 81, said he could understand why the all-white juries of the time would have returned a guilty verdict in such cases. "People were called 'nigger lovers'. Regardless of the circumstances, they would have been branded and they would have been outcasts," he said.

"There was mutual respect and we didn't have racial problems back in the '20s and '30s," Jones recalls.

Lee, now 81, still lives in Monroeville part time, but is rarely seen in public.

"Nelle [Lee's first name] is very unassuming, unpretentious. You may run into her in the grocery in jeans," said Mary Tucker, who moved to the town in 1954 and taught in both black and integrated schools.