Dr. Seuss, a.k.a. Ted Geisel, may have died in 1991, but his exuberant ability to engage kids of all ages lives on. In April 2025, three editors from Random House visited the library at the University of California, San Diego—near Geisel’s longtime home in La Jolla, California—for another look at the collection held by Dr. Seuss Enterprises. Among about 20 boxes of personal papers, they struck gold: a handwritten manuscript and a collection of proposed sketches that have now been fashioned into the latest Dr. Seuss classic.
“Our teams were originally researching materials relating to the early sketches of The Cat in the Hat and How the Grinch Stole Christmas! in anticipation of Dr. Seuss Enterprises’ ‘Year of Genius’ celebrations for the 70th anniversary of both titles in 2027,” says Susan Brandt, president and CEO of Dr. Seuss Enterprises. She says the discovery was “like finding a time capsule of his imagination.” What was thrilling, she adds, was that they would be able to publish Sing the 50 United States! in time to coincide with America’s 250th anniversary celebration.
In the new book, aimed at readers ages 3 to 7, the Cat in the Hat—plus two little cats first introduced in The Cat in the Hat Comes Back—delightfully help young readers remember the name and location of every state. (In a droll twist, the Cat and his helpers at first come up with only 49 states.)
Tom Brannon, who has worked on a number of other books in the Seuss franchise, including musical and board books, does an uncanny—and fantastic—job illustrating the latest posthumous book in Seuss’ style. The two most recent manuscripts discovered since Geisel’s death that have been published posthumously are What Pet Should I Get? (2015) and Dr. Seuss’s Horse Museum (2019).
Brandt and the editors say they did not have to change a single punctuation mark from Geisel’s original sketches and manuscript, which Brandt calls “a testament to his acute attention to detail.” However, pagination was another matter, Random House senior editor Cat Reynolds told Publishers Weekly. “There was no indication for page turns, so we worked on finding the moments that felt organic, where we might leave a little bit of suspense or have some iconic, fun art on the page.”
