President Lyndon Johnson had all of his telephone calls and many of his Oval office conversations recorded. It took decades to get the tapes and transcripts declassified and subsequently made available to the public.
In March of this year the Johnson Presidential Library released the last batch of material for the final year of his presidency - 1968.
For the first time those of us who are not special scholars learned a lot we did not know - including two stories that, had they been revealed at the time, could well have changed the course of American history.
In the summer of 1968, the Democratic National Convention was the backdrop for extraordinary street battles between anti-Vietnam War protesters and an aggressive Chicago police force. As President Johnson watched these bloody confrontations live on television, he could see his legacy in tatters.
So disregarding his commitment not to run again for president - and after being assured by Chicago Mayor Richard Daley that he could still win the majority of the delegates - Johnson decided to fly to Chicago to accept the nomination. However, given the almost war-like situation around the site of the convention, the Secret Service intervened, telling the president he would be at great risk and they could not guarantee his safety. Thus, a deflated Johnson did not go to Chicago.
Yet there was an even a bigger story in 1968, which has not received the attention it deserves.
Just five days before the presidential election, President Johnson went on television to announce that the North Vietnamese had made concessions at the Paris Peace talks that could end the Vietnam War almost immediately. However hours later, the South Vietnamese said no to the compromise. That much we knew.
There have been rumors and whispers about what might have happened - but we did not actually know why Saigon said no. Now we do, with as much certainty as we will ever have.
Johnson was told by then Secretary of Defense Clark Clifford that the FBI had secret wire taps in which Republican presidential candidate Richard Nixon’s designated emissary Anna Chennault, told the South Vietnamese not to accept the latest proposals. She urged them to wait until Nixon was elected when they would get a better deal.
Johnson was outraged. He called Nixon treasonous and said “he has blood on his hands.” Johnson gave this information to Senate Republican leader Everett Dirksen and Democratic presidential candidate Hubert Humphrey.
But - no one went public.
In 1968 America was already in turmoil over the Kennedy and King assassinations and wide spread anti-war riots. A revelation of this magnitude, on election eve, based on illegal wiretaps, could have been calamitous.
And so, Nixon would win the presidency by less than 1% of the popular vote. The war would continue for five more years and 22,000 more Americans troops would die. And it would be forty five years before Americans would learn crucial details about the actual history of 1968.