In the original story on which the pilot episode for this series was based, the hero was simply called Derringer. The first name, "Yancy," was added specifically for the TV series, which was produced by Desilu Studios.
The decaying Southern mansion seen on the series was the Tara set from Gone with the Wind (1939), which stood on the back lot at Desilu Studios (formerly Selznick International Pictures). The facade was sold and moved to Georgia later in 1959.