Swift has been wanting to write about Rebekah Harkness since 2013. When Swift talked about writing "The Last Great American Dynasty," she admitted that she's been wanting to write about the previous owner of her Rhode Island mansion for a while now but never figured out the right way to do it until she was creating Folklore. She added that the song certainly has that "country music narrative device" about telling one story about someone else and then inserting yourself into the narrative at the end.
William Bowery is Joe Alwyn. Of course, the biggest revelation in the film is that William Bowery, who cowrote a few tracks on the album, is Swift's boyfriend, Joe Alwyn. In addition to writing the melody for "Exile," Alwyn also recorded a demo of the track with Swift. Later in the film, Swift reveals that Alwyn also wrote the chorus of "Betty."