Maya Angelou, Maurice Sendak and John Steinbeck are among the authors being championed in the American Library Association's annual Banned Books Week.
Angelou's I Know Why the Caged Bird Sings is cited
All feature on the top 10 of books most frequently challenged in US libraries or schools during 2004 because of their content or appropriateness.
Banned Books Week, which runs until Thursday, hopes to raise awareness about the dangers of censorship.
Harry Potter and Huckleberry Finn have featured in previous campaigns.
However, this is the first time in five years that JK Rowling's works have not made the list of most targeted books.
"We firmly believe it is the right and responsibility of parents to make decisions about what their child reads," said Beverly Becker, associate director of the ALA's office of intellectual property.
However, she said no one had the right to ban books they considered "unsuitable".
Three of the most challenged books of 2004 - King and King by Linda de Haan and Stern Nijland, The Perks of Being a Wallflower by Stephen Chobsky, and Angelou's I Know Why the Caged Bird Sings - have been criticised for their homosexual themes.
Steinbeck's Of Mice and Men, meanwhile, has attracted complaints for its alleged depictions of racism and sexism and its use of violent language.
Robert Cormier's The Chocolate War topped the list, drawing the most complaints over its sexual content, language and religious viewpoint.
The ALA said it received 547 challenges last year, compared to 458 in 2003.
One of the more unlikely characters to figure in the list is Captain Underpants, a superhero challenged "for offensive language and modelling bad behaviour".
Sendak's In the Night Kitchen, meanwhile, attracted complaints for its use of nudity.
In the past 10 years, Roald Dahl's James and the Giant Peach, Harper Lee's To Kill a Mockingbird and JD Salinger's Catcher in the Rye have all made the Top 10.