Writer Ernest Hemingway appears in Cuba in 1948 in this photo provided by the John F. Kennedy Library and Museum.

Boston ? When Gaylord Johnson Jr. was struggling with a term paper at Phillips Academy in Andover, Mass., he figured he’d ask for help from someone who knew the material best: Ernest Hemingway.

“I’ve read a couple of the Nick Adams stories and have also read critical material on the same,” Johnson wrote in a letter to Hemingway in 1956, referring to one of Hemingway’s most famous characters. “I am, however, not quite satisfied with all I’ve read, and I wondered if you would write me and tell me just what you think of Nick Adams.”

Johnson’s letter, along with more than 3,000 other documents from Hemingway’s time in Cuba, was previously tucked away in the basement of Hemingway’s estate at Finca Vigia, unseen by scholars and researchers.

Now, thanks to an agreement between U.S. Rep. James McGovern, D-Mass., and the Cuban government, copies of those writings are at the John F. Kennedy Library.

The archival replicas include corrected proofs of “The Old Man and the Sea,” a movie script based on the novel, an alternate ending to “For Whom the Bell Tolls” and thousands of letters, with correspondence from authors Sinclair Lewis and John Dos Passos and actress Ingrid Bergman. The documents were previewed Thursday and will likely be available to researchers in late spring.

McGovern, museum officials and scholars hailed the agreement with Cuba as historic cooperation between the two countries.

“It’s a turning point toward a more rational, mature relationship between our two countries,” McGovern said. “I think Hemingway can be the bridge to help move both sides to a point where we can have a good, solid relationship.”

McGovern, an advocate of normalizing relations between the U.S. and Cuba, said Cubans consider Hemingway one of their own because he lived there for 21 years, longer than any other place he resided in his life.

The Worcester congressman also credited the Cubans working at Finca Vigia for scanning and digitizing all the materials and working to preserve the originals and the house in Cuba, which was also part of the agreement.

The JFK Library already has an extensive collection of Hemingway material — 100,000 pages of writings and 10,000 photographs, paintings and personal objects such as Hemingway’s passports, flasks and wallet — thanks to a connection between Hemingway’s fourth wife, Mary Welsh Hemingway, and the Kennedys.

Hemingway’s wife returned to Cuba in 1961 after Hemingway’s death that July, hoping to retrieve his belongings from his house at Finca Vigia. Because Fidel Castro had risen to power, she asked a friend who knew the Kennedys if President Kennedy could help her get to Cuba and take Hemingway’s possessions back to the United States. The president took care of logistics within days.