Ellsberg leaked the Pentagon Papers, a top-secret U.S. government study of decision-making in the Vietnam War, to The New York Times and other newspapers in 1971.

He had previously worked as a strategic analyst for the RAND Corporation and for the U.S. Department of Defense.

• He was charged under the Espionage Act of 1917, but the charges were dismissed in 1973 because of government misconduct, including illegal wiretapping.

• He later became a prominent advocate for whistleblowers and an activist against nuclear weapons.

• His attorneys included civil liberties lawyer Leonard Boudin.