For Richard Howorth, owner of Square Books in Oxford, Miss., To Kill a Mockingbird is unquestionably one of the most “beloved stories in all of American culture.” And more than just beloved, the debut novel by Harper Lee, who died last week at 89, is one of the rare works to have achieved as much critical success as commercial success. That the book earned such a prominent perch in this country’s collective imagination—a staple on school reading lists, as well as bestseller lists—became both boon and burden for a woman who scorned fame and prized privacy.

Mockingbird, published in 1960, has sold some 40 million copies to date, making it one of the biggest-selling American novels ever written. The fact that its author who hoped her early flirtation with literary stardom would be fleeting, and largely disappeared from public life after the book was published, only contributed to the novel’s mystique.

Having successfully stayed out of the limelight for most of her post-Mockingbird life, Lee became the center of national attention once again when, last year, HarperCollins announced it would be releasing a new novel she had written. Although Go Set a Watchman was not actually new—it was later revealed that the book was, in fact, an early (and initially rejected) first draft of Mockingbird—its publication became one of the biggest industry stories of 2015. The book became a huge hit as well: Watchman was the bestselling print book of 2015, moving 1.6 million copies, according to Nielsen BookScan.

Michael Morrison, president and publisher of HC’s General Books Group, said Lee was, more than just an iconic author, an incredible person. In a statement, he cited her “humility” and “kindness,” adding that she lived “the way she wanted to: in private, surrounded by books and the people who loved her.” Her agent, Andrew Nurnberg, said knowing Lee over the past few years “has been not just an utter delight but an extraordinary privilege” and that her death marked the loss of “a great writer, a great friend, and a beacon of integrity.” Lee’s death also brought an outpouring of condolences via social media, where the hashtag #HarperLee began trending shortly after the author’s death became public on February 19.

On Twitter, Oprah Winfrey, who selected Mockingbird for her book club, called Lee her “1st favorite author,” adding that Lee’s response to Winfrey’s request for an interview was, “Honey, I already said everything I had to say.” Reese Witherspoon, another fan, who narrated the audio edition of Go Set a Watchman, said, “[Lee] revealed it all... the glory and the fear and the hate and the beauty.” Author John Green, who gave his son the middle name Atticus (after the hero of Lee’s first novel), called Mockingbird “his most prized possession.”

For Southern bookseller Howorth, the author’s passing felt, in a way, like a blessing. “Given all the controversy surrounding Go Set a Watchman,” he said, “the news [of her death] seems to come with a sense of relief, more than anything. The expression rest in peace never seemed more apt.”

Correction: An earlier version of this story misidentified the owner of Square Books as Richard Jackson; Richard Howorth is the owner of the store. Additionally, while Howorth is a Southern bookseller, he is not Lee's local bookseller.