Her death was confirmed by HarperCollins, her publisher, which said the writer "died peacefully" Thursday night.
Pulitzer Prize-winning novelist Nelle Harper Lee, whose beloved book "To Kill a Mockingbird" was lauded as a classic of modern American literature that addressed racial injustice tolerance, has died. She was 89.
Her death was confirmed by HarperCollins, her publisher, which said the writer “died peacefully” Thursday night.
Lee was born on April 28, 1926 in Monroeville, Alabama, the youngest of four children of lawyer Amasa Coleman Lee and homemaker Frances Cunningham Finch Lee.
She attended Huntingdon College and studied law at the University of Alabama. She moved to New York in 1949, where she worked as an airline reservations clerk and wrote in her spare time.
When she was 31, she submitted a manuscript entitled "Go Set a Watchman" to publishers, including to J.B. Lippincott Company, which bought the manuscript and worked with Lee to retune it. Its finished form was retitled "To Kill a Mockingbird."
The novel, which was published on July 11, 1960, has sold more than 10 million copies and has never gone out of print.
Read: 'Harry Potter' Actor Alan Rickman Dies of Cancer Aged 69
Lee won the Pulitzer Prize for fiction for the book, which included several people and events that were inspired from Lee’s own life.
In 1919 her father represented two black men, a father and son, accused of murdering a white store keeper. The men were found guilty and were hanged and mutilated, and Lee’s father never tried another criminal case.
The 1962 film adaptation of the novel also garnered critical praise, winning three Academy awards, including Best Actor for Gregory Peck, who played Atticus Finch.
Lee also accompanied her childhood friend Truman Capote—who inspired the "Mockingbird" character Dill—to Holcomb, Kansas to research the murder of a farmer and his family. Their work would go on to become his best-selling book, ‘In Cold Blood,’ published in 1966.
She permanently returned to her hometown after her sister Alice became ill, settling into a private life in Monroeville, AL.com writes.
Lee suffered a stroke in 2007, the same year she was awarded the Presidential Medal of Freedom.
A companion to her critically acclaimed novel, "Go Set a Watchman," was published last summer. The book’s release caused many to speculate about Lee’s involvement in the project and the condition of the beloved writer.
“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,” Michael Morrison, President and Publisher of HarperCollins US General Books Group and Canada said in a statement.
Read: 'To Kill A Mockingbird' Actress Breaks Her Silence on 'Go Set A Watchman'
Her agent, Andrew Nurnberg, said the writer was “full of life” when he last saw.
“Knowing Nelle these past few years has been not just an utter delight but an extraordinary privilege,” he said in a statement. “When I saw her just six weeks ago, she was full of life, her mind and mischievous wit as sharp as ever. She was quoting Thomas More and setting me straight on Tudor history. We have lost a great writer, a great friend and a beacon of integrity.”
Scores of devastated fans took to social media to express their sorrow at the passing of Lee.
Quoting Lee on Instagram, actress Sophia Bush posted: “Everybody’s gotta learn. Nobody’s born knowing.”
“RIP Harper Lee. Thank you, thank you, thank you,” Bush continued.
Activist Erin Brockovich tweeted: “You know what... #TKAMB is a book that changed my life. Maybe i should write one. Harper Lee inspired me & hopefully I can pay it forward.”
Apple CEO Tim Cook also took to Twitter, writing: “Rest in peace, Harper Lee. "The one thing that doesn't abide by majority rule is a person's conscience."
Services for Lee have not been announced.
Watch: Celebrities Praise Vanessa Hudgens in 'Grease Live' After Dad Dies