LONDON (AP) ― He had a reputation as a literary recluse, but a trove of previously unseen letters written by J.D. Salinger to a British friend reveals a sociable man who took bus trips to Niagara Falls, ate fast-food hamburgers, enjoyed watching tennis and claimed always to be writing new work.

The 50 letters and four postcards have been donated to a British university, which made them public Thursday on the first anniversary of the author’s death at the age of 91. They show that the enigmatic writer of “The Catcher in the Rye” was an affectionate friend who enjoyed gardening, trips to the theater and church suppers ― and thought one restaurant chain’s burgers were better than the rest.

Chris Bigsby, professor of American studies at the letters’ new home, the University of East Anglia, said they challenge Salinger’s image as a near-hermit holed up in his New England home.

“These letters show a completely different man,” Bigbsy said.

“This is a man who goes on (bus) parties to Nantucket or Niagara or the Grand Canyon and enjoys chatting to people along the way.

“He goes to art galleries and theater and travels to London to see (Alan) Ayckbourn and (Anton) Chekhov plays. He was out and about.”

The letters were written to Donald Hartog, a Londoner who met Salinger in 1938 when both were teenagers in Vienna, sent by their families to learn German. They corresponded after returning home ― Salinger to try his hand as a writer, Hartog eventually going into the food import-export business.

The pair wrote to one another during World War II ― in which Salinger fought as a soldier in the U.S. Army ― but after a few years the friendship lapsed. Hartog’s daughter Frances said her father burned those early letters while clearing out the house prior to a move.

“When we were kids it was sort of a joke ― ‘My dad knew Salinger and burnt the letters,’” she said. “He was de-cluttering. He said, ‘I looked at them and just thought, this guy’s not going anywhere.’”

Hartog’s literary judgment was wrong. Salinger became a celebrity when “Catcher in the Rye” was published in 1951. The story of the angry but articulate 16-year-old Holden Caulfield has sold more than 35 million copies and remains a classic portrait of youthful rebellion.

The novel’s success drove the attention-shy Salinger even further from the limelight. For several decades he lived quietly in tiny Cornish, New Hampshire, whose inhabitants took pride in protecting his privacy and seeing off interlopers. He gave few interviews and published relatively little.

His last book, “Raise High the Roof Beam, Carpenters and Seymour,” came out in 1963. His last published work, the short story “Hapworth 16, 1924,” appeared in The New Yorker in 1965.

Hartog made contact with his old friend after the publication of an unauthorized biography of Salinger in the 1980s. They began writing to one another regularly, and in 1989 Salinger traveled to Britain for Hartog’s 70th birthday. The two friends went to the theater and visited a zoo, and Salinger met Hartog’s three children.

“I remember being not very keen on meeting him because I liked his writing and I was afraid it might spoil it,” said Frances Hartog.

She needn’t have worried. Salinger “was very relaxed, very genial and genuinely interested in my father and in us.”

Frances Hartog found the letters in a drawer after her father died in 2007. The family donated them to the University of East Anglia in Norwich, eastern England, which has well-regarded American studies and creative writing departments.

The university says it will make them available to researchers and members of the public on request.

After Salinger’s death, neighbors recalled him as an amiable and unassuming fixture in town, different from the recluse he appeared in memoirs by his daughter and a former lover, Joyce Maynard.

The letters to Hartog ― addressed to “Don” and signed “Jerry” ― help flesh out that picture. They are not the only surviving letters by Salinger, but they cover a period late in his life when he was at his most elusive.

Frances Hartog said she can see Salinger’s literary style ― “casual, conversational but very direct” ― in the letters. But their fascination lies in their small, everyday details. The eminent author enjoyed listening to the Three Tenors ― Jose Carreras was his favorite. He liked watching tennis and admired John McEnroe ― as well as Tim Henman, the perennially underperforming British player.

And he thought Burger King hamburgers were better than those from other chains.

The letters do little to solve one Salinger mystery ― did he leave behind a hoard of unpublished work? He is rumored to have left a stack of finished, unpublished manuscripts in a safe in his house in Cornish. A year after his death nothing has appeared, and his publisher and literary representatives remain silent.

Bigsby said the letters are full of references to writing ― but are frustratingly short on detail. At one point, Salinger mentioned a plan to expand “Hapworth” into a book. It never materialized.

“It’s clear from the letters that Salinger was writing all the time,” Bigby said. “He says how he’s been working all these years and it’s such a relief not to have to worry about publication because publication is a distraction.

“If he was telling his friend the truth, there should be an awful lot of material. But he doesn’t say what it is.”