In 1939, at the age of thirty-five, Theodor Seuss Geisel was tinkering with an invention that was doomed to failure. Geisel had published a few books under the name Dr. Seuss, but he was hoping that a device he had patented, the Infantograph, would be a money-maker at the techno-utopian New York World’s Fair, which was opening that year. “If you were to marry the person you are with,” the banner that Geisel designed for his pavilion asked, “what would your children look like? Come in and have your INFANTOGRAPH taken!” In the tent, a couple would sit side by side; a double-lensed camera would blend their features together, then plop a composite mug shot atop an image of a baby’s body. “It was a wonderful idea,” Geisel insisted, but, as a feat of engineering, it was more of an evocation of outlandish, off-kilter Seussian machinery than it was a functional prototype. After much fiddling, he scrapped his plans, admitting, “All the babies tended to look like William Randolph Hearst.”

In “Becoming Dr. Seuss: Theodor Geisel and the Making of an American Imagination,” a new biography by Brian Jay Jones, this anecdote is mostly played for a laugh. But the impulse behind Geisel’s gadget is indicative of deeper concerns. Ever since John Locke articulated his thoughts on education, we have puzzled over what to project upon the blank slate of a child’s mind, remembering the philosopher’s counsel that “the little, and almost insensible impressions on our tender infancies, have very important and lasting consequences.” As Geisel grew into his role as Dr. Seuss, beloved children’s author, he came to represent a distinctly American repurposing of those reflections on childhood. As the mass-media landscape shifted and expanded throughout his life, Geisel eventually came to recognize the vital role of children’s literature. “Children’s reading and children’s thinking are the rock bottom base upon which this country will rise. Or not rise,” he asserted in an editorial, from 1960, in the Los Angeles Times. “In these days of tension and confusion . . . books for children have a greater potential for good or evil, than any other form of literature on earth.”

The path to that realization was a long one, riddled with accidents and detours. The genius of Dr. Seuss was the outcome of a personal and artistic evolution that spanned every decade of the American century, and Geisel wouldn’t fully embrace his profession or achieve his most significant triumphs until midlife and beyond. He began his career as a hired hand, providing cartoons and illustrations for magazines, ads, and other people’s books. Though the ad work was lucrative, he would soon cast about for more meaningful creative outlets, including writing for children. “I’d like to say I got into children’s books because I had a burning passion, a great message to bring to the youth of the world,” he told an interviewer late in life, “but it was because I was going nuts.” As the Second World War loomed, Geisel also threw himself into political cartooning, railing against the pro-fascist, anti-Semitic isolationism of Charles Lindbergh and Father Coughlin. After the United States entered the war, he joined the Army Signal Corps and created propaganda films under Frank Capra’s watch. For a brief period after the war, Hollywood beckoned, but Geisel’s few film projects that saw fruition ranged from disappointing to disastrous.

Throughout this period, Geisel published about a dozen children’s books under the name Dr. Seuss, ranging from his first, “And to Think That I Saw It on Mulberry Street,” in 1937, to “If I Ran the Circus,” in 1956, which were generally greeted by enthusiastic reviews but middling-to-decent sales. For the first two decades of his career, Dr. Seuss was hardly a household name. But, as the baby boom was hitting its peak and Sputnik was prompting much hand-wringing about the state of American education, a vigorous debate over literacy was beginning to take shape, and Geisel found himself thrust to the forefront of the battle.

For decades, schoolteachers had been parking their youngest students in front of basal readers or primers, exemplified by the Dick and Jane series. The pedagogical approach underlying these primers assumed that beginning readers learned new words best by associating them with pictures and memorizing them through dutiful repetition. By the middle of the nineteen-fifties, this “whole word” or “look and say” method was just starting to face pushback from proponents of phonics-based instruction, most visibly in Rudolf Flesch’s influential polemic “Why Johnny Can’t Read.”

It didn’t help that Dick and Jane belonged to what many have dubbed the dullest family on earth. The books were plotless, littered with mind-numbing, repetitious quasi-sentences. (“Look, Jane. Look, look. See Dick. See, see. Oh, see. See Dick.”) The illustrations were stodgy and bland. Flesch deemed the series “horrible, stupid, emasculated, pointless.” The author John Hersey, in an article on the literacy debate, for Life magazine, was not much kinder, calling the books “namby-pamby” and “insipid,” and the pictures “terribly literal.” Hersey wondered why primers couldn’t at least feature the talents of gifted children’s-book illustrators, and he listed Dr. Seuss among their ranks.

The head of Houghton Mifflin’s education division took note. He challenged Geisel to write a primer that emerging or reluctant readers would actually enjoy, pleading, “Write me a story that first graders can’t put down!” But for a wordsmith as playful and unconventional as Dr. Seuss—someone fond of phrases such as “howling mad hullaballoo,” who invented animals like the Yuzz-a-ma-Tuzz—there was a big catch: to qualify as a first-grade primer, the text would have to be tightly restricted to a list of three hundred and fifty simple, pre-approved vocabulary words, supplied by the publisher, with a preferred limit of just two hundred and twenty-five words. Could Dr. Seuss deliver a page-turner that contained itself to no more than two hundred and twenty-five real, English, mostly monosyllabic words?

Geisel agreed to give it a shot. For months, he pored over the word list, at times moaning and thrashing about on the couch, awaiting inspiration. According to one telling, Geisel “finally gave it one more chance and said, ‘If I find two words that rhyme and make sense to me, that’s the title.’ ” He was on the verge of giving up when “cat” and “hat” caught his eye. Several more months of excruciating writing and rewriting followed, as he wrested a coherent story from the restrictive word list. (His editor, Saxe Commins, who’d worked with the likes of Sinclair Lewis and William Faulkner, took the project every bit as seriously as adult literature—“he’d spend an hour talking about three or four lines,” Geisel recalled.) When Geisel went to deliver the final manuscript of “The Cat in the Hat,” Jones writes, “he knew he had something new and very different in his hands.”

Further Reading More in this series on the power and pleasures of children’s books.

In Jones’s summation, “With its likable and somewhat subversive main character, galloping verse, and deliberate sense of humor, ‘The Cat in the Hat’ was everything that ‘Dick and Jane’ was not.” And yet Geisel had not exactly flouted the prevailing pedagogical approach; he’d turned some of its defects into merits. The stultifying repetitions of the typical primer had been replaced with joyously musical ones. Some of the cat’s most comically absurd escapades are entirely consistent with the look-and-say method, minus the terrible literalness that Hersey decried. What child hasn’t marvelled at the delightfully drawn and boldly hued books, and cup, and cake, and rake, and little toy ship and little toy man, and red fan, and fish, and milk on a dish (all plucked from that word list) as they teeter on the cat’s extremities? On the other hand, with its reliance on memorable rhyming pairs and word families, “The Cat in the Hat,” beginning with its catchy title, accentuated for early readers how sound and symbol correspond. The book served as a gateway to the phonics-based approach, which eventually supplanted the whole-word pedagogy.