There was one story Neil Sheehan chose not to tell. It was the story of how he had obtained the Pentagon Papers. The Pentagon Papers, arguably the greatest journalistic catch of a generation, were a secret history of United States decision-making on Vietnam, commissioned in 1967 by the secretary of defense. Their release revealed for the first time the extent to which successive White House administrations had intensified American involvement in the war while hiding their own doubts about the chances of success. [Sheehan] also revealed that he had defied the explicit instructions of his confidential source, whom others later identified as Daniel Ellsberg, a former Defense Department analyst who had been a contributor to the secret history while working for the Rand Corporation. In 1969, Mr. Ellsberg had illicitly copied the entire report, hoping that making it public would hasten an end to a war he had come passionately to oppose. Contrary to what is generally believed, Mr. Ellsberg never "gave" the papers to The Times, Mr. Sheehan emphatically said. Mr. Ellsberg told Mr. Sheehan that he could read them but not make copies. So Mr. Sheehan smuggled the papers out of the apartment in Cambridge, Mass., where Mr. Ellsberg had stashed them; then he copied them illicitly, just as Mr. Ellsberg had done, and took them to The Times. Over the next two months, he strung Mr. Ellsberg along. He told him that his editors were deliberating. In fact, he was ... working feverishly toward publication.