When the Clantons force Steven and Dodo to perform The Ballad of the Last Chance Saloon, originally, Dodo was to sing while Steven played the piano. Jackie Lane proved to be a mediocre vocalist and so Peter Purves reluctantly agreed to swap roles so that he sang the Ballad while Lane pretended to play the piano.
This was the first western made for British television.
In a humourous exchange, the series title is worked into the dialogue. The Doctor introduces himself as "Doctor Caligari," and Bat Masterson asks "Doctor who?" The Doctor then tells him he is correct.
This was the series' first attempt at a western, and, indeed, the first story in any medium principally set in the United States - though the First Doctor had briefly visited New York City in Flight Through Eternity (1965).
This serial's negative reception convinced Innes Lloyd there was no future for purely historical stories with no science-fiction content in Doctor Who.