17 June 1967 – The Vietnam War‘s heaviest air attacks in nine months are American strikes targeting railroads near Hanoi.
Additionally, on this day, U.S. Defense Secretary Robert S. McNamara commissioned a top-secret study titled “History of U.S. Decision Making Process on Vietnam Policy” regarding U.S. political and military involvement in Vietnam from 1945 to 1967.
‘In 1971 Daniel Ellsberg—who had worked on the study—came to oppose the war, and decided that the information contained in the Pentagon Papers should be available to the American public. He photocopied the report and in March 1971 gave the copy to The New York Times, which then published a series of scathing articles based on the report’s most damning secrets.’ (2) The report became known as The Pentagon Papers.[100]
Source: (1) Wikipedia, (2) History.com