The name Laura Ingalls Wilder conjures up wholesome images of bonnet-clad children running through sunny hay fields and Pa playing his fiddle in a snug Wisconsin log cabin.

But a newly released memoir written by the beloved Little House author is set to cast light on a darker, more realistic side to the author's pioneer childhood in 1800s Midwestern America.

Pioneer Girl was the original version of Ingalls Wilder's childhood written for an adult audience that she and her journalist daughter Rose Wilder Lane tried - and failed - to get published in the early 1930s.

It was not until this autobiography was expanded and edited for a junior readership that it eventually hit the shelves in 1932, as best-selling children's title Little House In The Big Woods.

But the original rough draft was preserved and now the South Dakota State Historical Society Press plans to release it under the name Pioneer Girl: The Annotated Autobiography this autumn, complete with original misspellings and idiosyncrasies.

The original copy of the world-famous books will offer up a starker, more realistic take on frontier life, with themes such as domestic violence, alcoholism and an ill-fated love triangle.

The Little House TV series of the 1970s and early 80s offered up an idyllic, sanitized version of Laura Ingalls' childhood

Back in the 1930s, publishers cut out scenes from much of the time the Ingalls family spent in Burr Oak, Iowa, and Walnut Grove, Minnesota, on the basis that they were unsuitable for children to read about.

In one particularly harrowing incident, one of Ingalls' drunken neighbours pours kerosene through the window of his house and sets it on fire before dragging his wife around by her hair. He only stops when Laura's father Pa intervenes.

The story also includes intriguing details of a love triangle "gone awry" - although it's not yet clear what characters are involved.

Even Pa, portrayed as a saintly figure in the books and subsequent Little House TV series, was apparently a more flawed character in real life.

The story includes one scene in which Mr. Ingalls skipped on paying rent to his landlord, deriding him as a "rich old skinflint" (very un-Pa like language, as anyone who has read the books will know).

Despite being pitched to children, the Little House series was stark at times, with the hardships of pioneer life clearly laid out in books such as Little House On The Prairie and The Long Winter - when the whole Ingalls family nearly starved to death after being cut off from vital supplies by snow on the railroads.

But it seems the first draft of Laura's books contains a few more gritty home truths about the family's time out West.

Melissa Gilbert as Laura Ingalls in the Little House series

Amy Lauters, an associate professor of mass media at Minnesota State University in Mankato, said: "That first version was blunt, it was honest.

"It was full of the everyday sorts of things that we don’t care to think about when we think about history.

"And it’s certainly not the fantasized version we saw on Little House on the Prairie, the television show."

The writer Laura Ingalls Wilder

Pamela Smith Hill, a biographer of Laura Ingalls Wilder and the lead editor on the autobiography, said: "You can read Pioneer Girl as nonfiction rather than fiction and get a better feeling of how the historical Ingalls family really lived and what their relationships were and how they experienced the American West."

"I am very excited to see people have access to this," said Sandra Hume, who helps organise Laurapalooza, a conference dedicated to the life of Laura Ingalls Wilder.

"Her life story has been pretty muddled because people get mixed up with the TV show and it’s nice to see an interest in people seeing basically what is the primary source."

Pioneer Girl: The Annotated Biography by Laura Ingalls Wilder is out this September

Photos: Rex Features