Harper Lee, the author of To Kill a Mockingbird, one of America’s most enduring literary classics, has died aged 89.

The news was confirmed by a city clerk in Lee’s hometown of Monroeville, Alabama.

Lee only wrote one other book besides To Kill a Mockingbird, Go Set a Watchman, which was published in July 2015.

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For many years, Lee, a shy woman with an engaging Southern drawl, lived quietly and privately, always turning down interview requests.

After suffering a stroke and enduring failing vision and hearing, she spent her final years in an assisted-living facility in Monroeville.

To Kill a Mockingbird was published in 1960 and earned Lee a Pulitzer Prize.

The book came to define racial injustice in the Depression-era South and became standard reading in classrooms across the world.

Go Set a Watchman, which featured the same characters from a very different point of view, surprised the literary world, with reviews describing the book as “distressing” and “disturbing”.

In Watchman, an older Atticus Finch had racial views that left the grown-up Scout — Mockingbird’s narrator — greatly disillusioned.

Spencer Madrie, owner of Ol’ Curiosities and Book Shoppe, a small independent book store in Lee’s hometown, said the world had lost a “brilliant mind and a great writer”.

“We will remember Harper Lee for her candour, her talent, and the truths she gave the world, perhaps before the world was ready,” he said.

Michael Morrison, the head of HarperCollins US, said: “The world knows Harper Lee was a brilliant writer, but what many don’t know is that she was an extraordinary woman of great joyfulness, humility and kindness.”

“She lived her life the way she wanted to — in private — surrounded by books and the people who loved her. I will always cherish the time I spent with her.”