San Diego, California - This year's Read Across America Day, which celebrates children's books, happened to fall on Dr. Seuss' birthday. The event is usually chock-full of references to the celebrated author's works and his characters. But this year was different.

Both former Presidents Barack Obama and Donald Trump referred to Dr. Seuss when celebrating literacy in America.

But this year, President Joe Biden didn't mention the writer.

Instead, as USA Today reported, the National Education Association (NEA) decided to put the spotlight on more diverse children's books, like Tiara's Hat Parade by Kelly Starling Lyons.

The NEA's move comes in the wake of a 2019 study found that only 2% of the human characters in the Dr. Seuss literary universe are people of color, none of which are female.

The NEA started Read Across America Say in 1998 in partnership with Dr. Seuss Enterprises. The NEA hoped that the whimsical characters would help inspire potential readers: "That was the strategy up front, so kids would see Dr. Seuss’s Cat in the Hat and spark some attention."

But the collaboration came to an end in 2018 and the focus of Read Across America has changed. This was reflected on Tuesday in Biden's proclamation, which drew attention for not referring to the Horton Hears a Who author.

On the same day, Dr. Seuss Enterprises announced that they would no longer be publishing six of the author's books including According to the company’s statement they made this decision after discussions with a panel of experts last year and determined that “These books portray people in ways that are hurtful and wrong.”

They continued, "Ceasing sales of these books is only part of our commitment and our broader plan to ensure Dr. Seuss Enterprises’s catalog represents and supports all communities and families."