In the late 1960s, the Vietnam War had become a grim stain on the American psyche. Unbeknownst to the public, top-level leaders were secretly expanding the conflict.
Daniel Ellsberg was a military analyst who dragged the ugly secrets of the military out into the light through the so-called Pentagon Papers. Ellsberg was one of a very few people who had access to classified documents about the war. Those documents spelled out, among other things, that the war was likely unwinnable, and that in spite of this, the military was broadening its list of targets and intensifying its bombing campaigns.
Ellsberg leaked copies of the Pentagon Papers to the New York Times, which broke the story. The Nixon administration attempted to bar the media from publishing more of the documents, but the Supreme Court intervened, allowing the media to unveil governmental deceit on a huge scale.