Electronic television developed during the 1930s. After World War II it quickly grew in popularity and replaced radio as the main information and entertainment medium.
Three networks—NBC, CBS, and ABC—dominated early TV. Live drama, variety, and quiz and game shows were popular during the 1950s.
Television matured in the 1960s, and its content became more professional. The public television network began in 1967. Cable TV grew slowly during this decade.
The 1970s saw TV programs criticized for excessive violence.
In the 1980s and 1990s, the three traditional TV networks lost viewers to cable and to VCRs. The Fox network became a major competitor.
The Telecommunications Act of 1996 had a significant impact on TV station ownership and also introduced program content ratings. Rules for the eventual conversion to digital TV were announced in 1997.
TV broadcasting has switched from analog to digital broadcasting. TV stations may use the digital signal to broadcast high-definition television or lower-definition programs among which viewers may choose. HDTV sets are in more than 50 percent of U.S. homes.
TV is universal, dominant, and expensive. Its audience is currently fragmenting into smaller segments.
The broadcast TV industry consists of program suppliers, distributors, and local stations.
Big conglomerates own the major TV networks, and large group owners control most of the stations in large markets.
Public broadcasting relies less on tax revenues and more on private sources of funding.
The Nielsen Company compiles both network and local station television ratings.
