Bonanza - Season 12 - Eps 23: Terror at 2:00
A racist and his henchmen steal a Gatling gun, with plans to massacre everyone - including the Cartwrights - involved in a peace treaty signing between the U.S. Army and the Paitues in Virginia City. The man's hope is that the tragedy will spark another war and eventually lead to the genocide of all Native Americans.
About Bonanza

Title: Bonanza
First Air Date: 1959-09-12
Last Air Date: 1973-01-16
Status: Ended
Rating: 7.516/10 (from 441 votes)
Language: EN
Seasons: 14
Total Episodes: 431
Network: NBC
Genres: Western, Action & Adventure, Drama, Family
Production Companies: NBC, NBC Studios
Synopsis
The High-Sierra adventures of Ben Cartwright and his sons as they run and defend their ranch while helping the surrounding community.
Cast

Lorne Greene
Ben Cartwright

Michael Landon
Joe Cartwright

David Canary
Candy Canaday

Tim Matheson
Griff King

Mitch Vogel
Jamie Hunter Cartwright