In 1930, a 63-year-old Laura Ingalls Wilder completed an autobiographical account of the first 16 years of her life. She called the non-fiction account of her rough childhood, written for adults, Pioneer Girl. Unfortunately, despite the help of her daughter Rose Wilder Lane—who was already a successful journalist and writer in her own right—publishers rejected the work. 

Of course, many of the same stories ended up as part of a series that sold over 60 million copies when Wilder was convinced to fictionalize (and soften) her life for a younger audience in the Little House books. With those books now a staple of American literature and many people's childhoods, it makes sense that a savvy publisher would dig up the old Pioneer Girl manuscript and make it available to the public. The problem is, they didn't make it available enough.

South Dakota State Historical Society Press published Pioneer Girl as an annotated autobiography—annotation and editing done by Pamela Smith Hill, who wrote a biography of Wilder in 2007—last November. The book offers a look at life in the American West that isn't smoothed over for children's consumption, and Hill's annotations add backstories and real-life drama to characters you might remember from the series.

Fans jumped at the chance to take a rawer, realer look at the beloved author. The initial print was just 15,000 copies, all of which had sold out by Thanksgiving. That left an additional 15,000 orders unfulfilled—not to mention the 30,000 Amazon orders that had yet to be met. Nancy Tystad Koupal, the director of the publishing house, explained to Slate that they never expected to need so many copies. "You have to understand—this is an academic book," says Koupal. "We felt we were taking a huge risk even to do [15,000]."

Luckily for them, what was intended as an academic book recieved a decent amount of media attention that elevated it to must-read status for Wilder completeists, of which there are apparently more than 15,000. Slate's review from last year states, "If you haven’t read the Little House books, in other words, Pioneer Girl is not the place the start. (Ideally, the place to start is at around 5 years old, snuggled up against your own Ma or Pa.) But for those who already adore the novels they inspired, this annotated edition of Pioneer Girl will deepen and enrich a great American story."

For now, if you want a copy of the book you'll just have to wait, probably until March. Unless you're willing to really pay for it: Due to the demand, "used" copies of the book are selling on Amazon for close to $400.