Unpublished novels and short stories by Arthur Miller that give a revealing insight into the mind of one of the 20th century’s foremost dramatists have come to light.

Their pages, both typed and handwritten, bitterly attack the injustices of American racism long before it was taken up by the civil rights movement. They also feature characters who can be identified as Miller and his first wife, Mary Slattery, whom he was to leave for Marilyn Monroe.

Written before Miller went on to dissect the empty values and moral decay of the American dream in his classics Death of a Salesman and The Crucible, they were among boxes of papers that he made available before his death in 2005 to the eminent scholar and novelist Christopher Bigsby.

Miller had never given anyone access to them before. He was wary of biographers picking over his life story and coming up with what he called “gossip” to explain his plays. But such was his respect for Professor Bigsby that he used to send him copies of his plays for critical analysis.

Miller opened up his personal archive to him after discovering that the professor wanted to write a key study. Arthur Miller: The Definitive Biography will be published by Weidenfeld & Nicolson in November. It will trace the story of a staunch liberal, the son of Jewish immigrants in New York, who risked imprisonment by defying the House Un-American Activities Committee, and condemning Senator Joseph McCarthy’s persecution of communist sympathisers in The Crucible. His other masterpieces include A View from the Bridge, a story of betrayal in an immigrant family, and All My Sons, about a manufacturer of faulty war materials.

The biography will cover the unpublished works, two novels from the 1940s and 1950s, and five short stories from 1938 to the early 1940s. The stories were rejected by magazines, draining the confidence of an impoverished, aspiring writer who had just left university in Michigan. Some of the passages were too explicit, their sexual content unacceptable at the time.

One of the stories, from 1940, gives an early insight into the tragic drama he was to write nine years later: Death of a Salesman. Titled Schleifer, Albert, 49 — like a death notice in a newspaper — it is about a failing salesman who commits suicide, just like Willy Loman, the character in the play that was to win Miller a Pulitzer Prize.

Professor Bigsby, the founder director of the Arthur Miller Centre for American Studies at the University of East Anglia, said that while the moment of the suicide in the short story is a subway train coming in, Loman drives off in his car to kill himself in a deliberate accident.

Although Miller’s writing is generally seen as a study in realism, he said: “The surprise is the stream-of-consciousness prose. Here, he was writing experimental prose at the beginning of his career.”

The novel about racism breaks off after about 180 pages, but it reveals valuable new material. Professor Bigsby said: “I hadn’t realised how actively concerned he was with race in that early period. We knew about his interest in anti-Semitism , but not black-white relations. When the civil rights movement came along, he was less active, but this shows he was very concerned about the situation of black Americans.”

The copyright of the unpublished material remains with Miller’s family. Professor Bigsby, whose latest novel, One Hundred Days: One Hundred Nights, was published last week, does not believe that the author would have objected to the short stories being published. However, he said: “The novel where he was working through his own life and his first marriage, and where the characters are extremely recognisable, he wouldn’t have put that out there.”

News of the discovery came as Miller’s first play on Broadway, The Man Who Had All the Luck, opened at the Donmar Warehouse in London.

Life imitates art

— Miller’s father, Isidore, a shopkeer and manufacturer of women’s wear, lost all his money in the stock market crash of 1929

— Miller relied on odd jobs to pay for his studies, including being a radio singer, truck driver and warehouse clerk

— Miller had to tour army camps to get ideas for his screenplay for The Story of GI Joe (1945) — he had avoided being drafted because of a football injury

Source: National Endowment for the Humanities; University of Michigan)

Explore Books

• Book Extracts

• Book Reviews

• Books Group

• Audio Books

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy