Dr. Seuss didn’t have an easy time selling the bittersweet story to publishers. “It was rejected 27 times,” says Guy McLain, who works at the Springfield Museum in Geisel’s Massachusetts hometown.

McLain has become a local expert on Dr. Seuss. He says Mulberry Street might have never been published — if it hadn’t been for a chance encounter Geisel had one day as he was walking home in New York City.

“He bumped into a friend … who had just become an editor at a publishing house in the children’s section,” McLain explains. Geisel told the friend that he’d simply given up and planned to destroy the book, but the editor asked to take a look.

It was a moment that changed Geisel’s life.

He said if he had been walking down the other side of the street, he probably would never have become a children’s author,” McLain says.