Literary milestones come and go, but one is looming that has particular resonance for nearly every living American who ever learned to read: March 2 marks the birthday 110th birthday of Theodor Geisel, the beloved children’s author better known as Dr. Seuss.

Sure, it’s an offbeat anniversary, but Geisel was always an offbeat kind of guy.

Over the course of his career, Geisel, who died in 1991, churned out more than 60 books. Many were award winners, and all were models of craft, fusing a unique voice and artistic style. They have enthralled children — and their parents — for more than 75 years.

The books have spawned movies (which Geisel resisted during his life) and TV classics such as “How the Grinch Stole Christmas!,” which Boris Karloff memorably voiced. They have been read on the floor of the U.S. Senate — Texas Sen. Ted Cruz recited “Green Eggs and Ham” in his 2013 Obamacare filibuster. And one book, 1950’s “If I Ran the Zoo,” put the word “nerd” into the lexicon.

Most important, his books have introduced millions of children to the joys of reading and the magic of wordplay.

Not bad for a Massachusetts native whose early career included ads for Flit insecticide, Essomarine motor oil, and World War II propaganda posters whose caricatures, including bucktoothed Japanese with slanted eyes, induce cringes in contemporary audiences.

The Seuss we know, however, is rooted in his manic joy and ability to tap into a child’s-eye view of the universe.

“I think that the key to Dr. Seuss’ enduring appeal lies in the spirit of playfulness that permeates his work,” said Jen Robinson, a children’s literature expert who oversees the website Jen Robinson’s Book Page. “He encourages children and adults to look at the world in different ways, whether this means upside-down, from the top of a tree or from inside a tiny speck.

“One can’t look at the ‘Whos down in Whoville’ without smiling over their joie de vivre, for example,” she said.

That Geisel’s first children’s book, “And to Think That I Saw It on Mulberry Street,” was published in 1937 surprises many, given that his books are often thought of as a post-World War II phenomenon.

“Mulberry Street” is a tale about a boy named Marco and his flights of fantasy while walking down said road. It bears the core hallmarks of Geisel’s later style, including galloping rhyme (inspired by the engine rhythms of the artist’s voyage on an ocean liner):

And that is a story that no one can beat

And to think that I saw it on Mulberry Street.

There is also Geisel’s trademark ink line, at once cramped and freewheeling, and, above all, the unfettered whimsy of a child’s imagination. (The book is also a testament to perseverance: It was rejected by 20 publishers before landing at Vanguard Press.)

The wordplay is striking.

Consider the opening lines to “The Cat in the Hat,” the 1957 chronicle of a brother and sister’s misadventure with a gangly, anthropomorphic feline sporting a red-and-white top hat:

The sun did not shine.

It was too wet to play.

So we sat in the house

All that cold, cold, wet day.

I sat there with Sally,

We sat there we two.

And I said, “How I wish

We had something to do.”

Mood, setting, conflict, ennui. Just like Samuel Beckett’s “Waiting for Godot,” except that something actually happens.

“Geisel’s works also endure because of his gift for creating rhymes that are fun to read aloud and easy to remember, but are not cloying or irritating,” Robinson said. “That’s no small feat. I think it’s this combination of playfulness and lyricism that makes Dr. Seuss’ works stand the test of time.”

While Geisel morphed into a writer — Seuss was his middle name — he began as an artist, working in black-and-white illustration and color. While his stories are engaging, it’s the artwork that grabs people’s attention.

“Seuss’ illustrations convey a sense of movement and anticipation,” said Ann Schwab, senior librarian in the Denver Public Library’s children’s section. “His loose style, curvy lines and use of white space engage the reader’s imagination. You can’t wait to turn the page to see what happens next.”

A major legacy

Geisel, who was inspired by essays about childhood learning, also has a major legacy in preschool and elementary school education. The National Education Association celebrates National Read Across America Day on his birth date.

“He showed the world that easy readers don’t have to be sterile,” said Terry Doherty, executive director of The Reading Tub, an advocate for youth literacy. “For me, the Dr. Seuss books walk the talk in showing us that engaging kids with books and helping them learn to read can be fun not just for children, but for adults, too.

“Dr. Seuss has helped eradicate those antiseptic and unnaturally clean primers that were the norm for so many years. He was a pioneer for a genre that is the linchpin in helping kids build a critical life skill.”

On a recent morning at The Bookies, a Denver book shop catering to young people, 10 preschoolers sat in front of Cae Dornfeld, a staffer and, on this day, story lady. The children were rapt, for the first book Dornfeld was to read was Geisel’s “Mr. Brown Can Moo! Can You?” It’s a sound-along story where the title character buzzes like a bee, choo-choos like a train and, of course, moos like a cow. The kids ate it up, as Dornfeld — no small voice talent herself — knew they would.

“He makes nonsense reality,” Dornfeld said of Geisel’s gift. “Kids are so creative. They really do tap into an imaginary world, and he’s right there with them.”

Geisel’s influence is ongoing, she noted. Not only has he spawned successors, such as the children’s author Mo Willems (“Don’t Let the Pigeon Drive the Bus!,” “Elephants Cannot Dance!”), but his own books remain timeless.

“I think it’s because he brings so much joy to early readers,” Dornfeld said. “Whether you are reading or being read to, he really inspires you to read.”

Ryan Howard, a staffer at Bookies, has been a Seuss fan since childhood.

“I was actually in my second-grade production of ‘The Lorax,'” Howard, 29, said. “It continues to be one of my favorites. I think that’s one of the pleasures of Dr. Seuss, that it has universal appeal across the generations.”

Cindy Thrasher of Aurora introduced the Seuss books to her family as a young mother. Now, as a grandmother to a 2-year-old girl, it’s a second-generation tradition. “I think that Dr. Seuss was a wonderful author, from ‘The Cat in the Hat’ to all the others,” she said. “He has a very recognizable style in every book he wrote.”

William Porter: 303-954-1877, wporter@denverpost.com or twitter.com/williamporterdp

The Denver Public Library’s Central Children’s Library at 10 W. 14th Ave. will hold a Dr. Seuss birthday party on March 1 at 10:30 am. The free event will include games, crafts, birthday cake and readings from some of his books.