Julia Child was hired by the OSS in the summer of 1942 for clerical work
Several well-known American public figures were spies during World War II, declassified documents have confirmed.
The celebrities include the chef Julia Child, the historian Arthur Schlesinger Jr, the film actor Sterling Hayden, and the baseball player Moe Berg.
The 750,000 documents published by the National Archives are part of a massive archive on the wartime intelligence unit, the Office of Strategic Services.
Founded in 1942, the OSS is considered to be a forerunner of the CIA.
It was responsible for collecting and analysing information required by the US military's Joint Chiefs of Staff, and for helping to organize guerrilla fighting, sabotage and espionage abroad.
The release of the OSS archive, including 35,000 top-secret personnel files, unmasks one of the last secrets of the wartime intelligence agency, which was disbanded after three years in 1945.
The National Archives said the papers included "initial applications to join the OSS; preliminary training and subsequent work assignments; pay, leave and travel documents; evaluations, basic medical information; and awards, decorations and discharge papers".
It was already known that Mrs Child - the doyenne of US television cookery shows, who died in 2004 - had worked for the OSS, but the documentation includes several new details about her history.
When Mrs Child applied to work for the agency, she admitted at least one failing - impulsiveness. In her OSS application, she included a note expressing regret that she had left a department store job because she did not get along with her boss.
Moe Berg was approached by the OSS because of his language skills
"I made a tactical error and was out," she explained.
The baseball player Moe Berg was recruited because of his knowledge of German and several other European languages.
Other public figures confirmed as former OSS spies are former Supreme Court Justice Arthur Goldberg; Kermit Roosevelt, the son of former President Theodore Roosevelt; John Hemingway, son of the author Ernest Hemingway; the movie director John Ford; and Miles Copeland, the father of Stewart Copeland, the drummer of the rock band The Police.
Elizabeth McIntosh, a 93-year-old former OSS agent now living in Woodbridge, Virginia, praised the release of the documents.
"I think it's terrific," she told the Associated Press. "They've finally, after all these years, they've gotten the names out. All of these people had been told never to mention they were with the OSS."