In the film, Kennedy is rowed across the Katama Bay Channel to Edgartown after the accident. Kennedy testified that he swam the 500 feet. How Kennedy returned to the mainland is one of the many inconsistencies with the events of that night. Columnist Jack Anderson reported a month after the incident that Kennedy was taken to shore by boat, as shown in the film.
The 'father' and 'son' that find the car in the water the morning after the crash are actually father and son in real life and were chosen from a photo of the father fishing with his son. They shot in Chappaquiddick, Ipswich, MA and Rosarito, Mexico.
The car, a late model Oldsmobile with a curb height overall of about 4 feet, was lying on its crushed-in top and the wheels were out of water at low tide. High tide at Edgartown that night came at 3:54 A.M., and its rise and fall is only 2 feet. The accident, if it occurred around 11:30 P.M., came at about two hours after low tide, and therefore there could not have been much more than 4 feet of water, and perhaps less, at the point where the car lay. The bottom is presumably sandy, since the entire island is made of sand. Senator Kennedy gave credit to Messrs. Markham and Gargan for having "dived" at "risk to their lives" in an attempt to reach Miss Kopechne. It would be more appropriate to refer to wading and stooping.
The bridge where they were driving on was the Dike Bridge on the eastern part of the island, that connects the main part of Chappaquiddick with a strip of beach that runs north/south. While there are some homes along that eastern strip of beach on the north end, the party was not at one of them. The mystery of why they were driving on Dike Bridge has never been answered.
The "Kennedy curse" refers to the various tragic events and deaths that have the Kennedy family throughout the years: Rosemary's botched brain surgery (lobotomy) in 1941, Joe Kennedy Jr.'s 1944 sudden death (plane crash), Kathleen "Kick" Kennedy's death in 1948 (plane crash), JFK and Jackie's loss of their infant son in 1963, the assassination of JFK in 1963, a plane in 1964 carrying Ted Kennedy and others that crashed killing the pilot and an aide, the assassination of Bobby Kennedy in 1968, Ted Kennedy being charged with leaving the scene at Chappaquidick in 1969, Ted Kennedy's son, Ted Jr., losing his leg in 1973, RFK's nephew Michael Skakel being charged with murder in 1975 (litigation pending), RFK's son David's death in 1984 (drug overdose), William Kennedy Smith's attempted rape charge in 1991 (he was acquitted), another RFK son Michael's death in 1997 (ski accident), and the deaths of John Kennedy Jr., his wife, and his sister-in-law in 1999 (plane crash).
When Ted is being chastised by his lawyers for his actions, they refer to his actions as "John Wayne stuff." Bruce Dern, who plays Joseph Kennedy, Sr. in this film, had previously appeared with Wayne in the film The Cowboys, killing John Wayne's character. It was one of Wayne's few on-screen deaths.
While the portrayed events take place in July, the background foliage is not the lush green of mid-summer. Rather, it's fading very slightly toward yellow, betraying the movie's having been shot towards the beginning of Fall.
This is another role where Kate Mara, who plays Mary Jo Kopechne in the film, is the victim of a tragic accident surrounded by uncertainty. Mara played hard-nosed reporter Zoe Barnes, who also suffered a tragic death by being pushed in front of subway train by Kevin Spacey's character, President Francis Underwood, in House of Cards.