“The Story of Ferdinand,” by Munro Leaf (Grosset & Dunlap)

The project began as a lark, an author’s hasty effort to write a children’s book manuscript for his artist friend to illustrate. Yet the resulting picture book, “The Story of Ferdinand,” became an immediate bestseller and cultural touchstone.

Both Adolf Hitler and Francisco Franco banned it. Gandhi and Franklin and Eleanor Roosevelt admired it. Published in 1936, the story of the peaceful, flower-sniffing bull written by Munro Leaf and illustrated by Robert Lawson is considered a classic of American children’s literature and has never been out of print.

A movie poster for “Ferdinand,” starring John Cena as the bull. (Twentieth Century Fox)

The book is now the basis for the animated film “Ferdinand,” which opens Friday in theaters, with the main character voiced by the wrestler-actor John Cena. (A 1938 Disney film adaptation won an Academy Award.) There are new characters, plot twists and some slapstick humor, but the film retains the “stay true to yourself” message at the core of the book. Perhaps it helps that one of the screenwriters is Tim Federle, who is an award-winning children’s book author.

" 'The Story of Ferdinand' is one of several examples of how a children's book went out into the pop culture and had an impact far beyond the library world," said Leonard S. Marcus, children's literature historian and author of "Minders of Make-Believe: Idealists, Entrepreneurs, and the Shaping of American Children's Literature."

“It was an appealing story that people could project their own fantasies on.” And, Marcus added, it “proved to be one of those rare books openly appreciated by adults as well as by children.”

Leaf wrote “The Story of Ferdinand” in less than an hour one rainy fall afternoon as a gift to his good friend Lawson. Contending that “dogs, rabbits, mice and goats had all been done a thousand times,” Leaf focused his story on a Spanish bull named Ferdinand who eschews fighting for flower-sniffing, refusing to fight even when forced to face the matador in the ring. Instead, Ferdinand sits down to enjoy the fragrance of the flowers adorning the hair of women spectators.

"It was one of those brainstorm books," said Anita Silvey, a children's literature expert and author of "The Essential Guide to Children's Books and Their Creators." "Leaf was the ideal picture-book writer. In the best ­picture-book tradition, he keeps it simple and allows both room for the child's imagination and for the artist's imagination."

Illustrator Lawson’s masterful black-and-white drawings perfectly complement Leaf’s text, adding energy and humor to the tale. In one famous example, Lawson depicts Ferdinand’s favorite cork tree with bunches of wine corks hanging among the leaves. “That’s part of what works so well — there is a complete interplay between words and illustrations,” Silvey added.

The timing of the book’s publication — just months after the start of the Spanish Civil War — proved a boon to sales as both sides excoriated it, while Hitler called it “degenerate democratic propaganda.” Others, including the Roosevelts, were fans of the book. Anne Carroll Moore, the first president of the New York Public Library’s children’s division, called it an “effortless, happy collaboration . . . designed for sheer entertainment of the ageless.”

Leaf insisted he had written the story of the gentle bull simply to amuse children. In a New York Times interview, Leaf said that Ferdinand’s aversion to violence merely manifested his “good taste and strength of character,” demonstrating that he was “just a superior soul, a philosopher.”

John Cena, left, and Ferdinand the Bull at the Los Angeles premiere of “Ferdinand.” (Willy Sanjuan)

Within a year of its publication, “The Story of Ferdinand” hit the bestseller list, which also included “Gone With the Wind.” In 1938, Walt Disney Studios won an Academy Award for its cartoon adaptation, “Ferdinand the Bull.”

Leaf and Lawson collaborated on two other books, including “Wee Gillis,” winner of a Caldecott Honor in 1939. “The Story of Ferdinand” never won an award, but it remains a timeless favorite.

“Controversy sells books, but it doesn’t keep a book in print,” Silvey noted. “It’s not the controversy that made this book a classic. It’s a just a fabulous story, one that children can really embrace, the idea that ‘I need to be who I am, not who others think I should be.’ ”

Karen MacPherson is the children's and teen services coordinator for the Takoma Park, Md., library.