The film was based on a 60-minute television episode that appeared on NBC in 1962 as part of the "The DuPont Show of the Week." Walter Matthau and Teresa Wright starred.
I saw this at the cinema. In the UK they changed the title to, Big Deal At Dodge City, even though thinking about it, Dodge City is never mentioned, & it obviously isn't Dodge City, but I don't think anyone noticed (or cared) at the time.