The Hangdogs is a group of tribals with a mixed reputation across the wasteland. Neither known for being particularly brutal or kind, The Hangdogs mostly keep to themselves, living in northeastern Colorado near Denver – or, as the NCR calls it, “Dog Town”. The Hangdogs run with packs of dogs that have been taken from the hordes that reportedly infest Denver. They worshiped dogs, and saw them as their spirit animals. Outside of their dog-focused culture, the Hangdogs act as slavers and scavengers, and are often in league with Hecate.
When Caesar's Legion arrived, the Hangdogs resisted them like most other tribes, but eventually lost to Caesar when he had their dogs burned alive. The tribe's elders were not able to bear the thought of their spirit animal burning in the after life, so they surrendered to Caesar. After they were integrated into the Legion, Caesar, seeing how useful the Hangdogs' talent were in taming dogs, made the male members of the tribe Houndmasters of the Legion, and Caesar also made the Houndmasters begin training and taming the Legion mongrels.
The following is based on Van Buren and has not been confirmed by canon sources.
Before the designers of Van Buren merged the Hangdogs with the Blackfoot tribe, Hangdogs could be found living near Denver. After the merge, the Hangdogs are a part of the Blackfoot tribe mainly helping out with guarding the tribes with their pack of dogs.