To Kill a Mockingbird — Harper Lee

Harper Lee's 1960 Pulitzer Prize-winning novel has been one of the most challenged books in American schools since the 1970s, facing objections for both its racial language and frank treatment of rape—a paradox that highlights censorship debates around historical texts. Over 50 challenges have been recorded since 2000, a rate 25% higher than the average challenged book in the U.S. during that period. Unlike #7 Lolita, which is banned for its narrative perspective, Mockingbird's challenges stem from the very racial injustice it condemns, making it unique among top-10 entries.