The narrator says that the assassination of President Kennedy occurred "exactly 100 years to the week from the Battle of Gettysburg, President Lincoln's finest moment." The Battle of Gettysburg occurred in July 1863. It might be that the narrator was referring to the delivery of the Gettysburg address which took place on 19 November 1863.
Several times the narrator mentions Special Prosecutor Leon Jaworski. Each time the clips show Sam Ervin.