"I'm Here to Kill a King" was originally scheduled to air on November 29, 1963. As fate would have it, the assissination of President John F. Kennedy occurred one week before this date. This episode's central plot element involving a political assassination obviously had the potential to affect the public sensitivity at this point in time, so "I'm Here to Kill a King" was pulled and replaced on the schedule with another episode. Apparently, according to TV listings published for the 1963-64 season, "I'm Here to Kill a King" was never aired during the first run of Route 66's fourth season, although the segment was later included in syndication.
Filmed in Niagara Falls, New York (October 5-16, 1963).