While declining ratings were a factor in the decision, the show ended primarily because the studio felt it would be competing with the then-new Disney Channel on cable TV. Today the Disney Channel rarely shows old Disney films or programs as they used to in the 1980's and '90's.
NBC was loyal to the show throughout the 1960s and most of the 1970s, but by 1979, ratings were declining, and they demanded changes in the format. The studio updated the visual look of the show with a disco theme song and a fancier opening sequence. This convinced NBC to renew the show until 1981. But the ratings did not improve and NBC canceled it. CBS then picked it up and featured an even more elaborate opening sequence using then-state-of-the art computer graphics. Disney canceled the show in 1983 due to the start of The Disney Channel. The show was revived in 1986 on ABC then moved to NBC in 1988. It was canceled in 1990 after 36 consecutive seasons on network television. In 1997, the show was revived by ABC as The Wonderful World of Disney (1997).
The Disney feature-length films were, at first, either edited down to one hour or broadcast in two or more weekly installments, one hour per week. It was not until the mid 1970's that the Disney Studios finally broadcast one of their feature-length films complete in one evening, the way all other films were usually telecast on network television.
Shown under five different titles, and eventually appearing on all three of the then-major television networks (ABC, NBC, and CBS), this was, and as of 2005 still is, the longest-running weekly prime time network show in the history of television. "Hallmark Hall of Fame" has run longer, but that has not been a weekly show in more than forty years.
All of the ABC episodes were filmed in color, even though they aired in black and white. In general, ABC did not broadcast in color until the mid 1960s. During the years on ABC, the show went by the title of "Disneyland", with one of four weekly sub titles,either "Fantasyland", "Frontierland","Adventureland" or or "Tomorrowland", depending on the category of that week's show. When the show moved to NBC, in 1961, the different sub titles were dropped. Additionally, many of the ABC episodes that re-aired on NBC were shown in color and have been that way ever since, even those episodes aired on The Disney Channel as well as those released in the theater ("The Adventures of Davy Crockett") and on home video.