Bonanza
Bonanza is an NBC television western series that ran from 1959 to 1973. Lasting 14 seasons and 431 episodes, "Bonanza" is NBC's longest-running western, and ranks overall as the second-longest-running western series on U.S. network television (behind CBS's "Gunsmoke"), and within the top 10 longest-running, live-action American series. The show continues to air in syndication. The show is set in the 1860s and it centers on the wealthy Cartwright family that live in the vicinity of Virginia City, Nevada, bordering Lake Tahoe. The series initially starred Lorne Greene, Pernell Roberts, Dan Blocker, and Michael Landon and later featured (at various times) Guy Williams, David Canary, Mitch Vogel, and Tim Matheson. The show is known for presenting pressing moral dilemmas.
Bonanza
NBC moved "Bonanza" to Sundays at 9:00 pm Eastern with new sponsor Chevrolet (replacing "The Dinah Shore Chevy Show"). The new time slot caused "Bonanza" to soar in the ratings, and it eventually reached number one by 1964, an honor it would keep until 1967 when it was seriously challenged by the socially daring variety show, "The Smothers Brothers Comedy Hour" on CBS. By 1970, "Bonanza" was the first series to appear in the Top Five list for nine consecutive seasons (a record that would stand for many years) and thus established itself as the most consistent strong-performing hit television series of the 1960s. "Bonanza" remained high on the Nielsen ratings until 1971, when it finally fell out of the Top Ten.