The show chronicles the weekly adventures of the Cartwright family, headed by the thrice-widowed patriarch "Ben Cartwright" (Lorne Greene). He had three sons, each by a different wife: the eldest was the urbane architect "Adam Cartwright" (Pernell Roberts) who built the ranch house; the second was the warm and lovable giant Eric "Hoss" Cartwright (Dan Blocker); and the youngest was the hotheaded and impetuous Joseph or "Little Joe" (Michael Landon). Via exposition (Bonanza, "Rose For Lotta", premiere September 12, 1959) and flashback episodes, each wife was accorded a different ethnicity: English (Bonanza, "Elizabeth My Love"; episode #65) Swedish (Bonanza, "Inger My Love", episode #95) and French Creole (Bonanza, "Marie My Love", episode #120) respectively. The family's cook was the Chinese immigrant Hop Sing (Victor Sen Yung). Greene, Roberts, Blocker, and Landon were billed equally. The opening credits would alternate the order among the four stars.
Elenco: Michael Landon , Dan Blocker , Bing Russell , David Canary , Lorne Greene , Lou Frizzell , Mitch Vogel , Pernell Roberts , Ray Teal , Tim Matheson , Victor Sen Yung .