An iconic children’s book heroine who observes friends, classmates, and neighbors – and holds nothing back in her notebook commentary – first came on the scene in 1964, when Harper & Row published Louise Fitzhugh’s Harriet the Spy. The author followed up that debut novel with two others featuring Harriet’s friends: The Long Secret, released in 1965, and Sport, published posthumously in 1979 (Fitzhugh died of a brain aneurysm in 1974 at the age of 46). On February 25, Delacorte, which acquired the rights to Fitzhugh’s Harriet books in 2000, will issue a 50th anniversary edition of Harriet the Spy.

The commemorative edition includes a new map of Harriet’s Manhattan neighborhood and “spy route”; tributes by 14 children’s book professionals; a letter that Fitzhugh’s editor, Ursula Nordstrom, wrote to her when the book was published; and early praise for the novel from poet Phyllis McGinley and author Elizabeth Janeway.

“I have always loved Harriet because of her unflinching honesty,” said Beverly Horowitz, v-p and publisher of Delacorte Press, who edited the new edition. “She is an aspiring writer and yes, she is a spy, not in the sense that she is solving a mystery, but in the sense that she is trying to figure out life. I think one way smart kids figure out life is by observing others. Harriet sees people make choices and sometimes make mistakes, and perhaps unconsciously learns a lot from that.”

Though the book has been consistently in print for five decades, Harriet the Spy received mixed reviews when it first appeared. Some criticized Harriet’s fierce independence (she does her spying alone, on occasion sneaking into a neighbor’s dumbwaiter to eavesdrop) and her sometimes less-than ladylike behavior. “From what I’ve read, a lot of people at the time were horrified that this girl threw a shoe at her father, had a tantrum, and didn’t want to apologize for all the things that I believe make her so interesting and honest – and a real individual,” said Horowitz. “Of course a lot of reviewers loved the novel and instantly got it, but there was certainly some negativity, mostly about the fact that Harriet wasn’t a good little girl.”

In a crucial plot twist, Harriet becomes an outcast when her peers get hold of her notebook and read the hurtful comments she’d written about them (“Pinky Whitehead will never change. Does his mother hate him? If I had him I’d hate him.”). Horowitz credits Fitzhugh for authentically depicting both Harriet’s and her friends’ reactions to the notebook revelations. “She lets us see both sides of the situation perfectly,” she said. “You can understand why Harriet’s friends would be angry, and you can understand why she is devastated and feels so lonely when they gave her the silent treatment. It is one of the many aspects of this novel that will resonate forever with middle-school kids.”

Harriet the Spy is timeless in other ways as well, Horowitz observed. “Harriet doesn’t have a cell phone or an iPad – she has a notebook, pencil, and her spy tools,” she said. “We aren’t giving kids enough credit if we think they only want to read about the technology of the moment and can’t move beyond that ‘stuff.’ The novel’s emotional intensity and honesty and Harriet’s reactions to her problems are so on target, and kids really respond to that. I don’t think that after a few minutes of getting to know Harriet as a personality any reader would say, ‘What year is this story taking place?’ It just doesn’t make any difference.”

Random House Children’s Books will kick off Harriet’s 50th anniversary celebration with a launch event at McNally Jackson in lower Manhattan on February 25, at which authors Rebecca Stead and Elizabeth Winthrop, both of whom contributed appreciations to the anniversary edition, will speak. Stead, Leonard S. Marcus, and Gregory Maguire are among the contributors scheduled to appear at an anniversary event at the 92nd St. Y on March 15. And the Eric Carle Museum of Picture Book Art is organizing an exhibition of Fitzhugh’s original drawings for Harriet the Spy. The exhibit will premiere at The Forbes Galleries in Greenwich Village March 7–May 3, and will be on view at the Carle in Amherst, Mass., May 20–November 30.

Booksellers interested in hosting a Harriet the Spy anniversary party event can access downloadable materials on the book’s Web site, and Harriet fans can share their memories of the book and heroine on Twitter using the hashtag #Harriet50th.

Insights and Tributes

The decision to include authors’ commentaries in the new edition of Harriet the Spy sprang from the publisher’s interest in offering substantive extra material to commemorate the anniversary, as well as from feedback Horowitz has heard over the years. “Whenever I ask people about their favorite book, they often cite Harriet the Spy, or say that the novel influenced them as a writer,” she said. “I did a little research and learned how important the book was to quite a few writers who themselves have had a great impact on children’s literature.” Here are comments from four authors who contributed appreciations to the anniversary edition.

Leonard S. Marcus, children’s book historian and author of Dear Genius: The Letters of Ursula Nordstrom, pointed out the avant-garde nature of the novel:

Harriet the Spy broke a laundry list of taboos when it was first published one year after Where the Wild Things Are, also edited by Harper’s Ursula Nordstrom. Harriet could almost be Max’s older sister, except for the fact that her father looks way too much like Mad Men’s Don Draper. She is a girl who dresses like a boy. She skulks angrily through the streets when she should be exhibiting the benefits of a fine Upper East Side address and dance lessons. (At one point, she tells her parents that she will ‘be damned’ if she will ever take dance lessons.) She commits the felony crime of breaking and entering. She betrays her friends. Her parents for their part drink like fish and take their daughter to see a therapist. None of this was typical of the young people’s fiction of the time, and it touched a cultural nerve.”

In her tribute, Judy Blume, whose canon includes Are You There God? It’s Me, Margaret and the Fudge novels, admired Fitzhugh’s candid depiction of real life:

“Finding Harriet as a young writer in the mid 1960s was inspiring. It meant I wasn’t the only one who wanted to tell stories about kids who were real. Louise Fitzhugh remembered what it was like to grow up and wasn’t afraid to write about it. She was one of the authors who most inspired me, who continues to inspire me.”

Rebecca Stead, author of the Newbery Medal-winning When You Reach Me and 2012’s Liar & Spy, wrote about Harriet’s – and her own – growth as a writer:

Harriet the Spy is a book about the emergence of a writer. Harriet is lonely, especially after her lifelong babysitter, Ole Golly, leaves. She struggles with the isolation of her internal life, rich as it is. At the beginning of the story, she writes in order to know herself and to understand others. By the end, she’s also writing to express herself and to connect with others. I read the book when I was 10, and recognized the emotion as true. I was just beginning to understand what fiction could do for me, that it was more than entertainment. Books like Harriet the Spy fed me in a way that came to feel essential. I didn’t know it then, but Harriet was an early step on the long, twisty path to writing.

“I think the book still feels powerful and fresh because it deals so honestly with the reader: no condescension, no fakery, nothing stilted about it. Every time I read it, I’m overcome by the certainty that Louise Fitzhugh said exactly what she wanted to say; she didn’t try to fit her story into any mold, and there’s something very compelling about that, even after 50 years.”

Meg Cabot, whose novels for teens include the Princess Diaries series, discussed key life lessons she learned from Fitzhugh’s novel:

“When I was nine, I loved Harriet the Spy for its ‘spy’ tips. I felt it was my duty to investigate potential ‘crimes’ that were being committed in my neighborhood, real or imaginary. I learned a lot more a few years later, when some private correspondence I had written about a certain girl I disliked fell into the hands of that very girl. Like Harriet, I was forced by my parents to send a written apology to that girl. I was shocked when she not only accepted it, but wanted to be friends, proving that it was some very convincing writing (I’d based it on Harriet’s example). What the novel showed me as a child is that words have the power to hurt, but they can also heal, and that it’s much better in the long run to use this power for good than for evil. This was a stunning revelation to me, as it was to Harriet. It made me want to see what else I could write (besides apology letters) that might make people feel better, as opposed to worse.”

Harriet the Spy: 50th Anniversary Edition by Louise Fitzhugh. Delacorte, $17.99 Feb. ISBN 978-0-385-37610-5