When the young Harper Lee published To Kill a Mockingbird on 11 July 1960, she didn't seem to see it as historically important. "I never expected any sort of success with it," she said much later. "I sort of hoped someone would like it enough to give me encouragement..."
In fact, the book was a huge success. An immediate bestseller, it won the 1961 Pulitzer Prize for Fiction. Since then, it has sold about a million copies every year, and been steadily translated into 40 languages. It has been voted the "best" and "most inspiring" novel in dozens of polls all over the world, and is a fixture on UK exam syllabuses and school reading lists. The book is such an essential part of the Western canon that it's hard to believe it is only 50 years old.
It is hard to believe, also, that its author is now an 84-year-old lady living in a retirement home in the small Alabama town where she grew up. But Ms Nelle Harper Lee is almost the perfect literary recluse. She has not given an interview since 1964, complaining that the questions are always the same. In the past decade, she has spoken briefly to The New York Times, written a charming paean to childhood reading for Oprah Winfrey's magazine O, and accepted the Presidential Medal of Freedom from George W Bush. But when asked in 2007 to speak to an audience in Alabama, she humbly refused, replying: "Well, it's better to be silent than to be a fool."
There are autobiographical elements to the only published book by Lee, who, just like her heroine, Scout, was the tomboy daughter of a small-town Alabama attorney. Her childhood friend was Truman Capote, who makes an appearance in the novel as Scout and Jem's friend, Dill. Capote helped Lee edit her novel, and she later helped him research In Cold Blood. He revealed that, when they were children, there was a man in their neighbourhood who "used to leave things in trees" and who obviously inspired Mockingbird's misunderstood loner Boo Radley.
Lee studied law – though, unlike Scout's father, Atticus Finch, played by the Oscar-winning Gregory Peck in the 1962 movie, she did not go on to represent any young black men on trial for the rape of white girls. "I'm afraid a biographical sketch of me will be sketchy indeed," she wrote when the book was published. "With the exception of M'bird, nothing of any particular interest to anyone has happened to me in my 34 years."
The themes in M'Bird are still powerful. Two of the books on this year's Orange Prize shortlist, Black Water Rising by Attica Locke (right), and Lorrie Moore's A Gate at the Stairs, explore racial tensions in modern America. But it's a rare book that inspires as much devotion as Lee's one-off. Many people still remember the first time they read it – and, if you haven't read it yet, you're very lucky. Just ask the people below...
The mockingbird and me: Ten public figures on Harper's finest hour
Shami Chakrabarti, Human-rights lawyer and director of Liberty
"I can honestly say I learnt more about human rights from To Kill a Mockingbird than all the law books in the world. I first read it when I was 12, then studied it at school. So much of what I believe about people and values is promoted in the simple but powerful story of Atticus Finch, who tirelessly defends a black man in the Deep South on the false charge of rape. At its heart it's really about three basic values: dignity, equality and fairness."
Charles J Shields, Harper Lee's biographer
"I was 13 when I read To Kill a Mockingbird. At that age, how Scout, Jem and Dill were trying to make Boo Radley come out of his house interested me more than the trial of Tom Robinson. But that's the key to why the novel works. The theme of tolerance is treated in two ways: a harmless man, Radley, is feared because he's misunderstood; a good man, Tom Robinson, is denied the protection of the law and the United States Constitution because he is black. You don't need to be an American from the South or to have grown up in the 1930s to appreciate the injustice on either, or both counts.
"When I visit high schools today, I'm struck by a paradox. Racism is not the issue it once was because the students are so diverse, yet To Kill a Mockingbird is all the more teachable. Now, the novel inspires discussions in the classroom about differences of religion, politics, lifestyle, and understanding "the other". The book has become a springboard for confronting forms of discrimination and hatred most readers wouldn't have considered 50 years ago.
"That's why it's good to re-read To Kill a Mockingbird now and again: it reminds you that it isn't easy to be a better human being, but it's important for all of us to try."
Duncan Preston, British actor, portrayed Atticus Finch in a recent stage interpretation
"I didn't read the book until I did the play, but I almost think it should be compulsory that everyone reads it. I felt so happy to be given the part of Atticus – he thinks like I do. I played the part for about six months or so, and I never thought at any point, 'I don't want to do this tonight.' It was such a joy to do. Even though the majority of the audience knows what's going to happen during the court scene, you could have heard a pin drop before the verdict. I think that, the way Atticus lets his kids listen to the case, he's a wonderful father."
Konnie Huq, Television presenter
"I read the book in my early teens and I remember watching the film on television. The central theme is about visualising being in someone else's shoes. It's all about being different. Being from an ethnic minority – especially at my first school, [where] there weren't many others from ethnic minorities – it really spoke to those issues. It has so many good messages that people will keep talking about it and studying it at school for years to come."
Xinran, Beijing-born British author
"How many 'mockingbirds' have been killed by one-sided justice on this Earth even before we could hear they had a song for us from their heart? Why do we have to simplify other cultures and beliefs into our black and white? Have we been honest to our human history, which has been written and taught mostly only by winners and victories?"
Tracy Chevalier, American author
"I first read To Kill a Mockingbird when I was 13. I remember having to write an essay on symbolism in the book for an 8th-grade English class. I chose Mrs Dubose's camellias. I can't recall now what they symbolised, but I do know that even having to read and write about the novel for school – often the kiss of death for a book – didn't kill my admiration. It is gripping and painful and funny. Scout and her father, Atticus Finch, are iconic figures to Americans. They do the right thing when it's called for, and it's a lesson readers don't mind learning."
Naomi Alderman, British author
"I can't remember if I read the book first, or saw the movie. But what sticks with me is Atticus. Or Gregory Peck. The combination of the two: the man who argues for justice even though he knows he must lose, who accepts public ridicule and violence as the wages of obeying his conscience, who continues not to doubt what is right. He is the perfect father: loving, calm and determined to teach good lessons. Every daughter, if she is lucky, sees Atticus Finch in her father from time to time."
Attica Locke, Orange-shortlisted American author
"I am the daughter of a lawyer, and was only a few years older than Jean Louise [Scout] Finch when I read Mockingbird for the first time. I read the book in my father's house one summer. I read the whole thing out loud because it was the first time I'd heard music in the language of my Southern upbringing. I was mesmerised. The setting, the characters, they were all deeply familiar to me. And no one was more recognisable to me than Atticus Finch. He, like my father, is a quiet, principled man, never showy or pushy, but still deeply moral and committed to the power of law. Both men have reminded me many times that in this life we are each other's keeper. I wrote my first short stories that summer, typing them on the back of my father's legal stationery. To Kill a Mockingbird will forever be connected, in my heart and mind, to my love of literature and storytelling."
June Sarpong, Television presenter
"I first read To Kill A Mockingbird when I was about 13. It had such a profound effect on me – instantly I was transported to the Deep South during the 1930s and the horrors of being a black person then. I felt an immediate connection with Scout – she reminded me of myself when I was six: inquisitive, feisty and somewhat innocently precocious. I'm not surprised Lee never wrote another book. What else is there left to say after you've penned one of the greatest masterpieces of the 20th century? To Kill a Mockingbird makes you, as a reader, look at what is both inspirational and flawed with humanity. Anyone who reads this book will be inspired to become a better version of themselves."
Robert Riley, Governor of Alabama, Harper Lee's home state
"For 50 years, schoolchildren and adults have read this classic novel and taken from it the important lessons taught by Atticus Finch. There is no better book to read this year, especially during its 50th anniversary of publication, than To Kill a Mockingbird."
50th anniversary paperback, hardback and audiobook editions of 'To Kill a Mockingbird' are published by Random House this week