After leaking the Pentagon Papers in 1971, the former military analyst joined the anti-Vietnam War and anti-nuclear movements.

Source: https://www.thepanamanews.com/2023/06/ellsberg-a-champion-of-the-truth-in-service-to-the-cause-of-peace/

He only found out that Sheehan had been lying to him when he was alerted by someone else at the Times the day before the first Pentagon Papers stories were splashed across the front page of the June 13, 1971, edition.

Source: https://theintercept.com/2023/10/07/pentagon-papers-daniel-ellsberg-neil-sheehan/

I think the Twitter files are the most important revelation we’ve had since, perhaps, the Pentagon Papers.

Source: https://www.lewrockwell.com/2023/03/no_author/new-conservatives-a-cause-for-optimism-an-interview-with-daniel-mcadams/

The Pentagon Papers did not change the outcome of the war; indeed, by the time they were released the Nixon administration already was for a “peace with honor” way out of the conflict.

Source: https://www.lewrockwell.com/2023/04/william-l-anderson/arbitrary-use-of-power-punishing-those-who-expose-not-so-secret-government-secrets/