During the Cuban revolution, Fidel Castro's forces were attacked by Batista's army at the foot of the Sierra Maestras in eastern Cuba. A government report claimed that forty of the rebels had been killed, including Castro. Only a few of them escaped into the mountains, among them Fidel, his brother Raul, and a gun-totting, asthmatic Argentinean physician, Che Guevara. These few survived with the help of people who lived in the mountains, while outside the Sierra Maestras few knew of the rebels' existence.

In early 1957, Herbert Matthews of the New York Times evaded army checkpoints, interviewed Castro, and returned to New York. Publication of the interview created a sensation and Cuba's minister of defense called the story a fantasy. The New York Times published a photo of Matthews and Castro, making the Batista regime look foolish. With the publication of this interview Castro gained the credibility and international support that allowed him to overthrow Batista's government. The Matthews Papers also include the working notes, manuscript, and typescript of his biography of Castro, published in 1969 by Simon and Schuster.

Matthews had Castro sign one page of his notes as further proof of the authenticity of his interview. That portion of the page was detached, and for a time was missing, but was eventually returned to Matthews who sent it along to join the other pages of notes, already given to Columbia.