That was what first-time screenwriters and executive producers Taylor Allen, 34, and Andrew Logan, 35 asked themselves when they heard the word on Bill Maher's show.
They knew who US Senator Edward "Ted" Kennedy of Massachusetts was, of course. But they had never heard of what historians have called the most famous and most documented car accident in American history, when Kennedy drove off a bridge into a pond on a Massachusetts island and his passenger, Kopechne, drowned in the submerged car.
"We Googled it but we misspelled it, so it took some time" to get the details, Allen says. But the facts are murky, obscured by myth, political partisanship, conspiracy theories and never-ending conflict between detractors and admirers of the Kennedy dynasty.
Chappaquiddick isn't a documentary, so it's difficult to parse how much of it is accurate and how much is fudged or the product of dramatic license. It's an ambiguous movie about ambiguity.
No independent scholar of the Chappaquiddick tragedy has come forward to endorse or condemn this movie. Political journalists aren't sure what to make of it, either. And the latest book on the tragedy has an entirely different theory, that Kennedy was actually with another woman in the car and neither of them knew Kopechne was asleep in the back seat.
No one from the Kennedy family or the Edward M. Kennedy Institute for the United States Senate in Boston agreed to talk to USA TODAY.
The senator's widow, Victoria Reggie Kennedy, "isn't commenting on the movie, nor is his family," family spokeswoman Stephanie Cutter told USA TODAY.
Kopechne's relatives also did not call back, but her aunt and her cousin wrote a column for USA TODAY saying they're happy with the "honest" movie and how it portrays her.
"Chappaquiddick is an honest recounting of American history, pivotal to understanding the lengths to which those in power will go to avoid accountability, protect their power and preserve their political viability," Georgetta Potowski and William Nelson wrote.
"We were pleasantly surprised with the care the producers, writers and cast took when tackling this movie, and pleased with their portrayal of Mary Jo's character and ambitions."
Chappaquiddick is a tiny island off Martha's Vineyard. Late on July 18, 1969, an Oldsmobile driven by Kennedy (played by Jason Clarke), 37, careened off the ramshackle Dike Bridge, plunging upside down in Poucha Pond.
Kennedy, a father of three with a pregnant wife, survived. Kopechne (Kate Mara), 28, a respected political operative, drowned. Her body was found the next morning in the back seat.
It happened the same week Neil Armstrong and Buzz Aldrin became the first Earthlings to walk on the moon — a historic story that dominated front pages and newscasts around the world.
It happened less than a year after Ted's brother, Bobby Kennedy, was assassinated as he campaigned for president. It happened less than six years after Ted's other brother, President John F. Kennedy, was assassinated in Dallas. It happened five years after Ted survived a plane crash in which his back was broken.
It happened as Ted was under pressure from his party and family to run for president.
Allen and Logan say they based their screenplay for Chappaquiddick on the official record. They say it is neither pro-Kennedy nor anti-Kennedy, it is pro-Kopechne and pro-truth.
"Even though I can be very tribal and a dyed-in-the-wool liberal, at the end of the day, the truth has no political party," Allen says.
Their film (directed by John Curran) attempts to reconstruct for a too-young-to-know audience what can happen when scandal strikes in an era of three networks, no cellphones, no Internet or social media, and way more trust in authority.
"It could never happen again in the same way, but now the audience's attention is so scattered by the deluge of (news), you can bury something by sheer volume," says Allen.
"Our naivety was one of our greatest assets because we did not know the questions not to ask, so we didn't get bogged with conspiracy theories," says Logan.
Allen says the screenplay "started out as a character study, became a thriller and finally became a way to honor a woman who was tragically underserved and misunderstood. We wanted to finally give her a chance to be a three-dimensional human being."
Logan says Kopechne's name has been "dragged through the mud for almost 50 years. This will bring to life the promising future she would have had."
What happened after the crash?
Kennedy called his actions on Chappaquiddick "irrational and indefensible and inexcusable and inexplicable."
He said he escaped through an open window, and tried to rescue Kopechne but couldn't reach her. Panicked, he said, he sought help at the party they'd been attending.
The film shows him lying about whether he had been drinking. It also shows he delayed reporting the accident for hours.
But did he really say, as he surveyed the submerged car with Kopechne inside: "I'm not going to be president"? Did he have nightmares about Kopechne whispering prayers as the water engulfs her?
The movie shows how a posse of former Camelot men, including ex-defense secretary Robert McNamara and JFK speechwriter Ted Sorensen, help contain the scandal, boss around deferential local cops and school Teddy in Cover-Up 101. No autopsy, they decree, and so it goes.
The nation's attention is focused on the moon while the clock runs out on newspaper deadlines and the PR team manipulates the press to "write what we want them to write."
A week later, Kennedy pleaded guilty to leaving the accident scene; he received a two-month suspended jail sentence. Then he addressed the nation.
The movie shows Kennedy asking his cousin and fix-it man Joe Gargan to write a resignation speech (dramatic license, Allen acknowledges). But Ted delivers a different speech in which he admits to bad judgment and explains he was overcome by grief, fear, doubt, exhaustion, panic, confusion and shock.
He did not resign, despite Gargan's entreaties. A year later, when Kennedy ran for re-election, he won with 62 per cent of the vote. When he did run for president, in 1980, he failed to get the Democratic nomination in large part because he couldn't answer coherently when asked in a TV interview why he wanted to be president.
He went on to become the long-serving and accomplished "lion of the Senate," who was widely mourned across party lines when he died of brain cancer in 2009 at the age of 77.
Chappaquiddick will be released in cinemas on May 10.
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