Susan Sontag’s novel In America (1999) is based on the story of the Polish actor Helena Modjeska, who came to California in 1876, where she found fame and fortune. Shortly after publication it was alleged that at least twelve of the book’s passages were plagiarized from four other books on Modjeska, one of which was written by Willa Cather.
Here is what Cather wrote: "When Oswald asked her to propose a toast, she put out her long arm, lifted her glass, and looking into the blur of the candlelight with a grave face, said: 'To my coun-n-try!'"
Now here is what Sontag wrote: "When asked to propose a toast, she put out her long arm, lifted her glass, and looking into the blur of the candlelight, crooned, 'To my new country!'" "Country," muttered Miss Collingridge. "Not 'coun-n-try'."
In her defense, Sontag, whose book contains no attributions, said in the New York Times Book Review : "All of us who deal with real characters in history transcribe and adopt original sources in the original domain. I've used these sources and I've completely transformed them. I have these books. I've looked at these books. There's a larger argument to be made that all of literature is a series of references and allusions."