He discussed with others Washingtons responses to the attacks on American ships in the Gulf of Tonkin by North Vietnam and the Cuban missile crisis in the 1960s.
However, the judge dismissed the case on the eve of the jurys deliberations due to government wrongdoing.
He enlisted in the Marines in 1954, breezed through officer candidate training, and then extended his enlistment so he could travel to the Middle East with his battalion in 1956 for the Suez crisis.
Daniel Ellsberg, a military analyst who made the historic decision to reveal the Pentagon Papers, a secret history of American lies and deceit in Vietnam, in 1971 passed away on Friday at his home in Kensington, California at 92.
Announcing the development in a statement, his wife and children revealed that the former military expert died of pancreatic cancer.
In an email to his friends and supporters in March, Mr Ellsberg disclosed that he had learned he had pancreatic cancer that was incurable and that his prognosis was three to six months.
In 1971, Mr Ellsberg made thousands of papers available to U.S.