March 2 is the birthday of the much beloved author Dr. Seuss (actual name Theodor Seuss Geisel). It’s also Read Across America Day, an annual event created by National Educational Association (NEA), the country’s largest literacy program. Millions of students and teachers will soon don the red and white stripes of the “Cat in the Hat” and read aloud from “Green Eggs and Ham” as part of this colorful tradition.

But as a February 26 NPR article explains, criticism about the depiction of people of color in the Swiss-born author’s books has captured mainstream attention. To describe a couple of those characters: a Chinese person (inexplicably wearing traditional Japanese shoes), replete with slashes for eyes, holds a bowl of white rice and chopsticks in “And To Think That I Saw It On Mulberry Street.” And men from Africa are shown shoeless and shirtless and exoticized in “If I Ran the Zoo.”

There has been some change: Read Across America is no longer synonymous with an uncritical celebration of Seuss’ work; in 2017 NEA rebranded the program, backing away from Seuss books. The same year, the NEA began highlighting more books by and about people of color on its website.

As NPR notes, only 2 percent of the human characters in Seuss’ books are people of color, and those depictions frequently devolve into racist caricature. Toddlers are the primary audience for his books, and research shows that by the tender age of 3, children begin to form racial biases that can become fixed by the age of 7. For this reason, the world of Seuss may have a disproportionate impact on race relations for future generations. And with more than 650 of his books in circulation, these troubling images are like the Cat in the Hat: they keep on coming back.

Read the full story on NPR.