Thank Oliver Stone's sensationalized 1991 movie for the JFK document release

Kevin Costner and Sissy Spacek (back left) in the film 'JFK', 1991. Photo / Getty Images

If and when the last remaining government documents about President John F. Kennedy's assassination are made public next week, historians may have to hold their noses and thank "JFK" - a 1991 blockbuster that conflated the historical record with conspiratorial fantasies.

Oliver Stone's barely factual retelling of a prosecutor's effort to prove the CIA killed Kennedy grossed hundreds of millions of dollars, and pushed Congress to order the release of nearly all assassination documents within 25 years, or by Thursday.

As the government agency called the Assassination Records Review Board once wrote, the film "disturbed" the public and elected officials with its suggestions of a secretive government coverup.

But as many reviewers and journalists have noted, "JFK's" most compelling scenes are totally made up.

In his defense, Stone never claimed the film he directed and co-wrote was truth.

"It is not a true story per se," he told the New York Times a few months before it was released in 1991. "It explores all the possible scenarios of why Kennedy was killed, who killed him and why."

But Stone promised a certain level of accuracy. He pointed the reporter to his studio's research department, stuffed with documents from the Warren Commission hearings and other investigations that concluded Lee Harvey Oswald, alone, killed Kennedy in 1963.

What ended up in theaters in time for Christmas opened like a documentary, with a montage of news footage from Kennedy's presidency and final motorcade.

But for the next three hours, Edward Jay Epstein wrote in the Atlantic, the film leapt seamlessly and confusingly between reality and fabrication.

It "demonstrated yet again how easily pierced is the thin membrane that separates the mainstream media from the festering pools of fantasies on its peripheries."

"JFK" is loosely based on the late-1960s trial of a New Orleans businessman, accused of conspiring with Oswald and the CIA to kill Kennedy.

A jury acquitted the man after less than an hour of deliberation, the New York Times wrote. The district attorney was accused of concocting bizarre theories to gain attention, and the trial left what the New Orleans Times-Picayune called "a lasting stain on the city's justice system."

But in "JFK," the trial was portrayed as a heroic effort to unshackle the truth from government clutches.

Jodie Farber reaches across the car in a scene from the film 'JFK', 1991. Photo / Getty Images

Two examples:

In the actual trial, a key witness recalled participating in the conspiracy only after being given so-called "truth serum" and hypnotized. In the movie, as Epstein noted, Stone simply swapped the problematic witness out for a fictional neo-Nazi with a good memory, played by Kevin Bacon.

Another key suspect in the alleged New Orleans conspiracy, David Ferrie, maintained his innocence until he died of natural causes, Epstein wrote.

But in "JFK," Epstein noted, Ferrie admits to working for the CIA, mentoring Oswald and knowing who Kennedy's real killers are - and is then promptly "murdered by a baldheaded man who forces pills down his throat."

For all the film's detailed fabrications, the New York Times complained in its review that Stone's central conspiracy "remains far more vague than the movie pretends."

"The conspiracy includes just about everybody up to what are called the government's highest levels," the Times wrote. "But nobody in particular can be identified except some members of the scroungy New Orleans-Dallas-Galveston demimonde."

The furor around the film only grew as it went on to win Oscars, and Stone defended the research behind it.

"I had never made a movie where I had to defend it six months later in the press," Stone recalled to Variety. "The media was very nasty and they'd set me up on shows. At some point I had quite a bit of research on my side, but I'd have to recall it all [on the spot] and I couldn't do that."

And yet, as the Assassination Records Review Board wrote several years later, the film successfully "popularized a version of President Kennedy's assassination that featured U.S. government agents from the Federal Bureau of Investigation, the Central Intelligence Agency, and the military as conspirators."

Though "JFK" was largely a work of fiction, the board wrote, the government wasn't helping dispel mistrust by keeping investigative reports on the assassination under seal until 2029.

So less than a year after the film hit the big screen, facing reelection, President George H.W. Bush signed the President John F. Kennedy Assassination Records Collection Act - promising to release all relevant documents by this month, unless doing so would threaten national security.

John F. Kennedy. Photo / Getty Images

The government began to make good on the promise almost immediately, in 1993, when National Archives workers wheeled out boxes stuffed with more than 800,000 pages of once-secret documents.

As The Washington Post noted at the time, the papers largely proved a disappointment to conspiracy theorists who lined up to sift through them, containing nothing to refute conclusions that Oswald acted alone.

But Stone, like fans of his movie, was not dissuaded.

"I'm amazed there is any single adult left in the U.S.A. who would not think that Lee Harvey Oswald was the one and only assassin," he wrote in USA Today in 2013, for the 50th anniversary of Kennedy's death.

The "counter-evidence" was still being stifled, Stone wrote, and accused the powers that be of replicating "a Soviet-era manufacturing of history in which the mainstream media deeply discredit our country and continue to demean our common sense."

And the public appears to still be with him.

While belief that others were involved in Kennedy's death has dipped since the 1990s, it was still the viewpoint of a solid majority of the American public - as it has been in Gallup polls ever since the assassination.

President Donald Trump said he plans to release the final assassination documents next week - a quarter century after "JFK" was released, and twice that long since the assassination.

As the Chicago Tribune wrote, whatever is in the papers is certain to inspire conspiracy stories for the future.