At first, the producers absolutely did not want Jaclyn Smith in the title role for this picture because they feared she was typecast as Kelly Garrett from Charlie's Angels (1976) and felt it would be a distraction to the picture. They eventually agreed to allow her to do a screen test, but her manager refused this, stating that they could watch any episode from 5 years on Charlie's Angels (1976) to get a feel of her screen persona. In a compromise, her manager had Smith do a recorded voice test which was then submitted and she was unanimously accepted by the production staff and granted the role.
James Franciscus (John F. Kennedy) previously played a fictionalised version of JFK named James Cassidy in The Greek Tycoon (1978).