- Actor-Shared Background: Like Allan Pinkerton, Angus Macfadyen is a native of Glasgow, Scotland.
- Backed by the Pentagon: According to this article, the producers received assistance from the present day Pinkerton company, who provided "access to authentic memorabilia, historic case files from their archives and consulting and expertise."
- California Doubling: Set in Kansas City, the series was filmed near Toronto and Winnipeg.
- The Cast Showoff: "Think of the Children" has Martha MacIsaac singing (very well) and Jacob Blair dancing (sort of).
- International Coproduction: Set just after The American Civil War, filmed in Canada, partially financed by Japanese companies (which probably explains why Kenji and Miyo are in the cast).
- No Export for You: The complete series is on DVD — but only in the UK.
- Screwed by the Network: As this show was a First-Run Syndication television series, some of the stations that aired it didn't give it support by burying it in odd timeslots (e.g. WPIX in New York City aired this show on Sundays at 1 PM, an hour not known to gain high ratings) and airing little to no advertising.
- Working Title: "The Case of the Dead Dog" was originally called "Caine Unable", a name that made it into some TV listings before the episode aired.
Trivia / The Pinkertons