Every biographer shares a special moment with a subject, a feeling of closeness, recognition, even love. For Anne Boyd Rioux, author of the new book “Meg, Jo, Beth and Amy: The Story of 'Little Women' and Why It Still Matters,” that moment came on a trip with her mother and her daughter Emma.

They had visited great literary houses in New England, the homes of Nathaniel Hawthorne and Emily Dickinson, and then they got to Concord, where Louisa May Alcott lived and worked at Orchard House.

Taking a tour, Rioux and Emma were the first two to enter the room where Alcott wrote “Little Women.” “And there it all was,” Rioux said. “It was not just the space where she wrote but the space she lived in.”

She teared up at the memory. It was a perfect space to share a mother-daughter moment, celebrating the author of a book long passed down from mother to daughter.

Fresh from the success of her most recent literary biography, “Constance Fenimore Woolson: Portrait of a Lady Novelist,” (which garnered coveted front-page coverage in the New York Times Book Review in 2015), Rioux, a professor of English at the University of New Orleans, was casting about for a new subject. Long drawn to books about books, she thought of writing a book about “Little Women,” and when she discovered the 150th anniversary was only three years away, she got to work, seeking grants and doing research.

The result is a warm investigation of the life of a classic American novel; its author Louisa May Alcott, who drew on her own family history for the story, particularly for its main character, Jo March; an analysis of what the novel has meant to women then and now; how it is read as a feminist text; various treatments in television and film; and Jo March’s descendants — such heroines as Katniss Everdeen and Hermione Granger.

So why has this book endured, never out of print, for 150 years?

It is a memorable tale of a mother and four daughters, struggling to survive in the Civil War era while the father is away. It is funny and smart and shows family life at its best; the girls are beloved characters, none more than the tomboy Jo, who chafes at restrictions and longs for an independent life as a writer. On the path to growing up, the girls must make tough choices.

Rather than encountering the book as a young girl, as many women do, Rioux first read it in graduate school. “But it still made my head explode!” she said. “And the questions were the same for me then. Who am I? Where am I going?”

As she pursued her study of 19th-century female writers, her interest in Alcott grew. “I realized, writing this, that she’s been influential in a way that is unlike any other woman writer,” Roux said.

Alcott, the second-eldest daughter of eccentric transcendentalist philosopher Bronson Alcott, grew up sharing the rarefied air of Thoreau and Emerson, who sometimes provided financial assistance to the beleaguered Alcott family. (Bronson’s idiosyncratic ideals often prevented him from working.) Louisa Alcott wrote journalism as well as romance novels under a pseudonym.

“I wanted to understand women creators,” Rioux said, “what it was like for them, what kind of chutzpah, maybe even selfishness it required. Remember, she wrote for money to help her family. And she became one of the best-selling writers of the era. She made a good living.”

She also became an unlikely celebrity. Rioux recounts that Alcott was likely to dash out the back door when fans appeared at the front seeking an audience.

Her repeated readings of “Little Women” have shown Rioux that it is a book that can “grow” with a reader. So it is that a young woman who thinks she is Jo may marry and become Meg, or even Marmee when she has children. Many of the tough choices for women’s lives remain the same.

“Alcott was called unladylike, but she wasn’t just the woman behind the character,” Rioux said. “It’s not that she was forgotten; it’s that she was undervalued, just like the whole category of girls literature. This book doesn’t get the recognition it deserves.”

And while Rioux brings her critical sensibilities to bear on the book, “it wasn’t sacred to me the way it was to many fans,” she said. “I could watch, I could read the different adaptations. I had a relation to the book as a cultural artifact. But I had to be aware of how cherished and loved this book was.”

At her book launch at Latter Library in September, many women turned up with their own memories of reading the book, of having it given to them by mothers. “I AM Jo March,” said retired UNO anthropology professor Martha Ward.

Generations of girls have felt the same way, which accounts for the many film and television adaptations. Among the most recent is the BBC miniseries, which was aired on PBS last summer. Still to come is a film, to be directed by Greta Gerwig and begin production this month, featuring Saoirse Ronan, Meryl Streep (as Aunt March), Emma Stone, Florence Pugh, Emma Watson and Laura Dern. The more the merrier, said Rioux.

In the course of her work, Rioux met with a book club at McGehee School to discuss the book. She explores why “Little Women” is or is not read today, especially interested in why it was not read by boys. Noted Louisianian James Carville said it was a childhood favorite, and best-selling authors John Green and Stephen King are fans. And Rioux edited a beautiful new Penguin Classic edition of the book, with a foreword by Patti Smith.

Rioux places "Little Women" alongside such contemporary works as the HBO series "Girls" and "Sex in the City," as well as “Harry Potter” and “The Hunger Games.” And of course, "Gilmore Girls." As Rioux writes, the themes of “Little Women” — “the tensions between family and self, sisterhood and separation, growing up and failing to find one’s way” — all remain relevant today. Louisa May Alcott, like her character Jo March, has made her mark on the world. And that is something to celebrate.

Susan Larson hosts "The Reading Life" on WWNO.