I don't think there's that much truth to your observation. "The Great Gatsby" only entered the public domain last year, while its Wikipedia entry says it "was

I don't think there's that much truth to your observation. "The Great Gatsby" only entered the public domain last year, while its Wikipedia entry says it "was part of the assigned curricula in the near majority of U.S. high schools". "'The Grapes of Wrath' is frequently read in American high school and college literature classes due to its historical context and enduring legacy" says its Wikipedia page, and it's still in copyright. In 1981, "Catcher in the Rye", according to its Wikipedia entry "was both the most censored book and the second most taught book in public schools in the United States." Salinger didn't die until 2010.