High Quality Content by WIKIPEDIA articles! Bonanza is an American western television series developed and produced by David Dortort and broadcast in the United States for 14 seasons on the NBC network. The entire run of the series` 430 hour-long episodes were photographed and aired in color. The premiere was on September 12, 1959, and the final episode broadcast on January 16, 1973. In its initial season Bonanza aired on Saturday evenings and placed at number 45 in the Nielsen ratings. During its second season the series moved up to number 17.Bonanza was moved to Sunday nights at 9:00 PM at the start of its third season. In that time slot the ratings soared and the series become second only to Wagon Train as the most popular program on American prime time television. It remained in the top ten of the ratings until its twelfth season and ranked at number one in its sixth, seventh, and eighth seasons.Bonanza also became a worldwide success as it was broadcast in nearly 50 countries, including Canada, Brazil, Yugoslavia, the United Kingdom, France, Italy, Switzerland, Saudi Arabia, Thailand, Australia, and Japan.