Book bans in public schools continued to surge in the first half of this school year, according to a report released on Tuesday by PEN America, a free speech organization.

From July to December 2023, PEN found that more than 4,300 books were removed from schools across 23 states — a figure that surpassed the number of bans from the entire previous academic year.

The rise in book bans has accelerated in recent years, driven by conservative groups and by new laws and regulations that limit what kinds of books children can access. Since the summer of 2021, PEN has tracked book removals in 42 states and found instances in both Republican- and Democratic-controlled districts.

The numbers likely fail to capture the full scale of book removals. PEN compiles its figures based on news reports, public records requests and publicly available data, but many removals go unreported.

Here are some of the report’s key findings.

Book removals are continuing to accelerate

Book bans are not new in the United States. School and public libraries have long had procedures for addressing complaints, which were often brought by parents concerned about their children’s reading material.

But the current wave stands out in its scope. Censorship efforts have become increasingly organized and politicized, supercharged by conservative groups like Moms for Liberty and Utah Parents United, which have pushed for legislation that regulates the content of library collections. Since PEN began tracking book bans, it has counted more than 10,000 instances of books being removed from schools. Many of the targeted titles feature L.G.B.T.Q. characters, or deal with race and racism, PEN found.

Florida had the highest number of removals

Florida’s schools had the highest number of book bans last semester, with 3,135 books removed across 11 school districts. Within Florida, the bulk of bans took place in Escambia County public schools, where more than 1,600 books were removed to ensure that they didn’t violate a statewide education law prohibiting books that depict or refer to sexual conduct. (In the sweep, some schools removed dictionaries and encyclopedias.)

Book removals have spiked in Florida because of several state laws, passed by Gov. Ron DeSantis and a Republican-controlled legislature, that aim in part to regulate reading and educational materials.

Florida has also become a testing ground for book banning tactics around the country, said Kasey Meehan, the program director of PEN America’s Freedom to Read Program.

“In some ways, what’s happening in Florida is incubated and then spread nationwide,” she said. “We see the way in which very harmful pieces of legislation that have led to so much of the book banning crisis in Florida have been replicated, or provisions of those laws have been proposed or enacted in states like South Carolina and Iowa and Idaho.”

Books depicting sexual assault are increasingly being targeted

With the rise of legislation and policies that aim to prohibit books with sexual content from school libraries, books that depict sexual assault have been challenged with growing frequency. PEN found that nearly 20 percent of books that were banned during the 2021-2023 school years were works that address rape and sexual assault.

Last year, several books that deal with sexual violence were removed from West Ada School District in Idaho, among them a graphic novel edition of Margaret Atwood’s “The Handmaid’s Tale,” the poetry collection “Milk and Honey” by Rupi Kaur, Jaycee Dugard’s memoir, “A Stolen Life” and Amy Reed’s young adult novel, “The Nowhere Girls.”

In Collier County, Fla., public school officials — aiming to comply with a new law that restricts access to books that depict “sexual conduct” — removed hundreds of books from the shelves last year, including “Their Eyes Were Watching God,” by Zora Neale Hurston; “A Time To Kill,” by John Grisham; and “The Bluest Eye” by Toni Morrison.

A movement to counter book bans is growing

Opponents of book bans — including parents, students, free speech and library organizations, booksellers and authors — are leading an organized effort to stop book removals, often with the argument that book bans violate the First Amendment, which protects the right to access information.

Last fall, hundreds of students in Alaska’s Matanuska-Susitna Borough School District staged a walkout to protest challenges to more than 50 books. At a school board meeting last October in Laramie County, Wyo., students held a “read-in” to silently protest book bans. Elsewhere, students have formed banned books clubs, held marches and created free community bookshelves in their towns to make titles more accessible.

Legislatures in California and Illinois have passed “anti-book ban” laws. In several states, including Texas and Florida, lawsuits have been filed in an effort to overturn legislation that has made it easier to ban books.

“In nearly every case that’s come forward, judges have been finding that these laws are unconstitutional,” said Jonathan Friedman, who oversees PEN America’s U.S. Free Expression programs. Still, Friedman said it could take years for the laws to be challenged and possibly overturned, and noted that new legislation keeps proliferating.

“I don’t have the sense that this issue is about to go away,” he said.