Around 3,000 previously unreleased documents, and more than 30,000 that have been released before but with redactions will be released.
The assassination of JFK on 22 November, 1963, birthed possibly the most enduring conspiracy theory of them all and the new information will be pored over for any evidence that Lee Harvey Oswald either didn't fire the fatal shots or did, but did not act alone.
First things first - there is a zero percent chance they will say anyone but Lee Harvey Oswald was responsible.
Despite serious questions about the official inquest, and theories purporting that organised crime, Cuba or a cabal of US security agents was involved, conspiracy theorists have yet to produce conclusive proof Oswald acted in consort with anyone.
Hugh Aynesworth was a reporter for the Dallas Morning News when the assassination happened and is the only person who witnessed first-hand JFK's death, Oswald's arrest and his murder by Jack Ruby.
He told the Guardian: "There is no other gunman. I guarantee it. Who in the world would like to expose, quote, 'the real story' more than me? I've been involved since the minute it happened, every step of the way."
So what will we find out?
Philip Shenon, the author of a book on the assassination, said he did not think the last batch of papers contained any major bombshells, but may shed light on the activities of Oswald while he was traveling in Mexico City in late September 1963, and courting Cuban and Soviet spies.
"I've always considered the Mexico City trip the hidden chapter of the assassination. A lot of histories gloss right past this period," Shenon said.
Oswald boarded a bus in Houston on 26 September, 1963, bound for the Mexican border. He spoke to other passengers on the bus and told them he was planning the travel on to Cuba.
Reaching Mexico City on the 27th, he applied for a transit visa to visit Cuba at the Cuban Embassy, telling officials his eventual destination was the USSR.
But his efforts were scuppered, as the Warren Commission recorded:
The Cubans would not, however, give him a visa until he had received one from the Soviets, which involved a delay of several months. When faced with that situation Oswald became greatly agitated, and although he later unsuccessfully attempted to obtain a Soviet visa at the Soviet Embassy in Mexico City, he insisted that he was entitled to the Cuban visa because of his background, partisanship, and personal activities on behalf of the Cuban movement. He engaged in an angry argument with the consul who finally told him that "as far as he was concerned he would not give him a visa" and that "a person like him [Oswald] in place of aiding the Cuban Revolution, was doing it harm."
Shenon said: "From the record we already have, we know he met there with Soviet spies and Cuban spies and other people who might have wanted to see Kennedy dead.
"Oswald was meeting with Soviet spies and Cuban spies, and the CIA and FBI had him under aggressive surveillance. Didn't the FBI and CIA have plenty of evidence that he was a threat before the assassination?
"If they had acted on that evidence, maybe it wouldn't have taken place. These agencies could be afraid that if the documents all get released, their incompetence and bungling could be exposed.
"They knew about the danger of Oswald, but didn't alert Washington.
"It's going to be very interesting to see what else the government knew about the threat Oswald might pose – how much more they learned about his trip in Mexico City and whether or not they bungled evidence to suggest he was a threat."
This is perhaps why there is still reluctance from US intelligence agencies regarding the publishing of the archive on Thursday.
The assassination of JK cut short "Camelot," as the 1,000 days of the Kennedy presidency became known. Kennedy was 46 and remains one of the most admired US presidents.
Thousands of books, articles, TV shows, movies and documentaries have been produced about the assassination and surveys have shown a majority of Americans still distrust official evidence pointing to Lee Harvey Oswald as the sole killer.
Shenon said it would be interesting, too, to see if there was anything in the documents to substantiate comments Trump made during his election campaign linking Texas Republican Senator Ted Cruz's father to Oswald.
"It's the president's favorite conspiracy theory about the Kennedy assassination ... but I don't think there is," Shenon said.
Cruz's father Rafael has called Trump's allegations that he was pictured with Oswald in New Orleans before the assassination "ludicrous."