S.E. Hinton's now-famous novel The Outsiders was published in 1967 when Hinton was just 18 years old. She started writing the book when she was 15 and wrote most of it during her junior year in high school. In later interviews, Hinton explained that she wrote The Outsiders because she felt that most of the books that people her age were expected to read were not realistic and did not include relatable characters or concerns. Hinton's novel, on the other hand, tackled issues like gang membership, class divisions, and the tragic loss of friends and family members.

It took a few years for the trend to catch on, but The Outsiders and its sequels were so successful that publishers began to seek out authors who could write compelling stories with teenagers at the center, interacting and behaving in realistic ways. By the 1980s, young adult literature as a category was firmly established in bookstores and libraries and included stories about additional serious issues facing American teens, such as divorce, mental illness, dating violence, and even suicide.

Today, the category is even broader. For instance, many novels with less realistic details, such as stories set in fantasy worlds or characters with futuristic special powers, are now considered young adult fiction if the characters in them are young people. Also, older adults may be just as likely to read and enjoy young adult novels--long after they've left their teen years behind.