The Columbia Broadcasting System grew out of a collection of radio stations purchased by William S. Paley in the 1920s. After CBS became one of the largest radio networks in the country, the company set its sights on television. TV broadcasting began in the 1930s but was not a major commercial force for the company until the 1950s.
In its heyday, CBS was often called the Tiffany Network, about the perception that its programming was of a higher quality than that of its competitors. Eventually, CBS became one of the Big Three broadcast networks in American television, along with NBC and ABC.
Beginning in the 1980s, CBS began to struggle. The advent of cable television didn't help its fortunes. Finally resurgent in the 21st century, the network once again climbed to the top of the heap among broadcast networks. With the introduction of its CBS All Access streaming platform, it began to work its way into online digital distribution.