ONE DAY in February 1926 an unknown American writer walked out of a New York snowstorm and into history. An important piece of that history is now in danger of being lost forever, caught in the controversy over the US trade embargo against Cuba. The unknown writer was Ernest Hemingway, and the New York office he walked into was that of Maxwell Perkins, the most famous American literary editor of his day. It is difficult to conceive -- 80 years and an incandescent literary career later -- the idea of publishing the 26-year-old Hemingway was a big risk. Hemingway had not yet published a novel. Indeed, his only published fiction consisted of a few short stories and poems, mostly in obscure Paris literary journals. Yet Mr. Perkins, as Hemingway was to call him for years afterwards, even after they had become close friends, took the risk. On the spot, he offered Hemingway a deal included a generous $1,500 advance on an unfinished, unnamed novel that Perkins had not even seen. Hemingway and Perkins began a correspondence that lasted for 21 years, until Perkins&39;s death in 1947. A number of those letters are now housed in Cuba, at Finca Vigia, where Hemingway lived longer than anywhere else. But the house is in danger of collapse. A group of Americans is trying to save the house and its contents. Yet the US government won&39;t let them. The Treasury Department recently turned down the Hemingway Preservation Foundation&39;s application for a license to permit its architects, engineers, and consultants to travel to Cuba to research a feasibility study to help the Cubans save Finca Vigia. This denial, which is contrary to the letter and spirit of the law, is being appealed.