Pre-production
Frankenheimer spent 1968 traveling with Robert F. Kennedy during Kennedy's presidential campaign; Frankenheimer was a close friend of Kennedy: right before his assassination, Kennedy stayed at Frankenheimer's home in Malibu then gave him a ride to the Ambassador Hotel, the site of the assassination.
According to Frankenheimer, "if you want to date a moment when things started to turn, it was after that night. I went through sheer hell. I went to Europe, and I just lost interest. I got burned out. I was really left very disillusioned and went through a period of deep depression. It took a long time to get it back." After the assassination, Frankenheimer spent five years in France, "taking cooking classes and directing sporadically." One of those films was I Walk the Line, originally titled September Country.
Frankenheimer wanted Gene Hackman to play the sheriff, but Columbia Pictures insisted that Peck be cast in the lead since he was under contract to them. Frankenheimer cast J.C. Evans, his wife's grandfather, who was eighty-two years old, to play the sheriff's father; the director called Evans "quite wonderful" but eventually had Will Geer dub his part.
Read more about this topic: I Walk The Line (film)