From 1948 to 1952 virtually all television broadcasting took place in three large population corridors: the Northeast (Boston, New York, Washington, D.C.); the Great Lakes rim (Detroit, Chicago, Milwaukee), and the West Coast (Los Angeles, San Francisco). With a relatively sophisticated urban audience to serve, the fledgling TV networks experimented with programming ideas. The teleplay (also known as the kitchen drama) remains the most critically celebrated of these. Usually performed live, these dramas could not offer outdoor shooting or special effects. They were forced instead to depend on psychologically oriented plots delivered with crisp dialogue by actors in confined spaces. The necessity of strong writing was made even greater by the fact that the teleplays did not make use of weekly recurring characters or situations. Several teleplaywrights, including Paddy Chayefsky (Marty, 1953), Reginald Rose (Tragedy in a Temporary Town, 1955), and Rod Serling (Requiem for a Heavyweight, 1956), became favorites of the new TV audience. Large corporations invested in full sponsorship of weekly prime-time teleplay showcase series, putting their names on such series as Philco TV Playhouse, the U.S. Steel Hour, and Ford Theater.

Another live, theatrically based form, the comedy-variety program, won a measure of praise from critics as well. If the teleplay was a televised adaptation of legitimate theater, the comedy-variety show was vaudeville in front of a camera. This eclectic genre made use of slapstick (such as could be found in the work of Milton Berle), broadly played pantomime (Jackie Gleason, Red Skelton), and witty, sometimes sophisticated blackout sketches (Sid Caesar). Here too Fortune 500 companies rushed to identify their products with these popular shows: Texaco Star Theater; the Colgate Comedy Hour; the Buick Circus Hour.

With the lifting of the freeze in 1952, the character of television programming began to shift, first slowly, then decisively away from the live theater aesthetic. New stations brought television beyond the limits of the largest cities to the Bible Belt, the Corn Belt, and the burgeoning family-centered suburbs that were being built across the country. The audience eager for psychologically realistic dramas and slapstick comedy sketches became a shrinking percentage of the whole as the number of television households mushroomed. With only three networks, and all of them intent on delivering audiences in the tens of millions, there was little room for minority tastes.

By the end of the 1950s the anthologized teleplay was dead, and comedy-variety was dying. Live television had virtually disappeared from prime time in favor of filmed (that is, prerecorded), editable programming. As the prices paid for individual television commercials skyrocketed into the hundreds of thousands of dollars, advertisers demanded finished products that could be shown to sample audiences and focus groups and then refined to suit test results. Telefilm series and situation comedies, genres capable of building audience loyalty with recurring characters and settings, became the rule in prime time. A homogenized collection of crime shows, medical or courtroom dramas, and family sitcoms dominated prime time throughout the 1960s and 1970s. Perhaps the single most exciting aesthetic development of the period was the introduction of full-color TV schedules by all three networks in the mid-1960s.

Also during this period, the networks made deals with Hollywood movie studios to broadcast feature films after they had completed their runs in the theaters. These proved popular, and soon the number of theatrically released films available for network broadcast could not keep up with demand. This led to the practice of making feature-length films expressly for television. Usually two-hour broadcasts (including commercials), these made-for-TV movies resurrected the anthological form. They occasionally provided some relief from the repetitive oversimplifications that were prominent in weekly series by probing matters of social importance; for example, Brian's Song (1971), concerning the previously taboo subject of cancer; That Certain Summer (1972), about homosexuality; and Fear on Trial (1975), concerning blacklisting in the entertainment industry.

From approximately 1960 to 1985 NBC, CBS, and ABC enjoyed an imperial rule over television and arguably over American popular culture in general. On any given evening, the three networks collectively held a ninety percent share of the prime-time television audience, which always numbered in the scores of millions. They presented virtually identical types of programs, most of which were made by a handful of production companies that supplied product to all three. Any cultural enterprise that did not appear on television became, almost by definition, countercultural. This is illustrated most clearly in genres of protest music and independent film that briefly flourished during the 1960s. If a work of human expression could not be “cleaned up” for TV, it could not find a truly national audience. If a work or a performance was cleaned up for TV, it might well sacrifice the very qualities that had made it distinct.

The other societal function subsumed by television in the last half of the twentieth century was the mass dissemination of news and current affairs. In the early years of commercial radio broadcasting, little was done beyond the reading of news or the dutiful programming of public affairs shows. In some cases pioneer radio announcers simply bought a local newspaper and read aloud from it over the air. Newspaper publishers were quick to understand the threat of broadcasting, and many responded by establishing or buying their own radio stations, and later TV stations. These can be counted among the first modern multimedia companies.

A great acceleration in the importance of newscasting was brought about by the advent of World War II in 1939, and the United States's entry into the conflict two years later. The speed with which radio reported war news from around the world redefined the role of the newspaper. No longer the primary source of breaking news, print journalism became a supplement to electronic journalism. The number of newspapers and newspaper readers in America would continue to decline for the rest of the century.

CBS chairman William S. Paley made a concerted effort to build up the network's news division, establishing bureaus in major cities around the world and hiring high-caliber journalists, mostly recruited from the print world, to act as editors and reporters, including such seminal figures as Edward R. Murrow and Howard K. Smith. As the nation looked to radio for war news each evening, CBS emerged as the voice of the war, positioning the company for dominance in the dawning television era. In 1948 CBS initiated a daily fifteen-minute television news summary, Douglas Edwards and the News. But the real impact of early TV on public opinion was made in prime time. In 1952 vice-presidential candidate Richard Nixon, accused of accepting illegal campaign gifts (including a dog named Checkers), bypassed a hostile press and went directly to the American people on television, dog in tow, to defend himself in his famous “Checkers speech.” It is credited with saving him from being dropped from the Republican ticket. Ed Murrow's exposé of Senator Joseph McCarthy's red-baiting tactics, aired on his See It Now series in 1954, was a key factor leading to McCarthy's censure by the U.S. Senate later that year. These telecasts demonstrated TV's extraordinary power as a political tool, even at this early stage.

The importance of the TV news anchor began to crystallize when NBC News, after playing second-fiddle to CBS since the radio era, scored a great success by teaming two of its correspondents, Chet Huntley (in New York) and David Brinkley (in Washington), in a daily half-hour telecast in 1956. In the 1960s CBS reasserted its dominance by establishing its daily news anchor, Walter Cronkite, as “the most trusted man in America” (according to several public opinion polls and the legends that grew up around him). ABC, the weakest of the three networks in terms of cash and affiliates, did not reach parity with the other two in news until the late 1970s, when a nonjournalist, Roone Arledge, was brought in from ABC Sports to head the network's news division. ABC's use of flashy techniques, such as color graphics and “lifestyle” interviews, alarmed some traditional journalists, but audiences responded well and TV news began to take on a postprint character as ABC's success created a new industry model.

The three networks also allowed their news divisions to present hour-long documentaries during their prime-time schedules, despite the fact that these programs were consistent money-losers. CBS Reports was the most notable of these series, presenting programs that explored such topics as the plight of American agricultural workers (“Harvest of Shame”), the destructive effects of dichloro-diphenyl-trichlorethane (DDT) and other pesticides (“ The Silent Spring of Rachel Carson”), and corruption in the military (“ The Selling of the Pentagon”). This level of fierce muckraking—and journalistic integrity—would not be reached again in commercial television.

During the radio era the United States stood alone among the western democracies in declining to develop a government-supported public broadcasting network, thus creating no complement or alternative to its huge broadcasting-for-profit industry. At first it appeared that this would remain true of television as well. Similar to what had occurred with radio, a disparate group of local stations supported by universities and nonprofit foundations took to the air, their number swelling to over one hundred by 1960. With little money to purchase programs or to produce them in-house, many of these educational stations (as they were then called) could stay on the air for only a few hours a day. Some devoted at least part of their broadcast schedules to classroom instruction in conjunction with local school boards. In 1963 the noncommercial stations formed a loose confederation known as National Educational Television (NET). Although they were not tied together to operate as a national network, they managed to exchange their best programs through a practice called bicycling, a reference to the fact that a program had to be physically transported from one station to the next, rather than telecast via network connections. Offering the only real alternative to homogeneous “big three” commercial entertainment, NET stations presented a collection of documentaries, fine arts performances, nature shows, and talking-head interviews. Much of this was funded by the Ford Foundation, which had made a long-term institutional commitment to foster this kind of television.

In 1967 the Johnson administration created the Corporation for Public Broadcasting, a congressionally funded agency whose purpose was to provide seed money for the production of programs. As a result a new entity, the Public Broadcasting Service (PBS), was born. It gradually absorbed the functions of NET and moved toward national programming. Series such as Nova (science documentaries), the MacNeil-Lehrer Report (a daily news program that had begun as a NET production), and Sesame Street (for children) were among PBS successes, although audiences remained tiny by commercial standards. The greatest ratings successes for PBS came in the 1990s with two documentary miniseries, The Civil War and Baseball, both produced by filmmaker Ken Burns.

Rather than funding public television with a dedicated tax (in the manner of the BBC), an annual funding request must be approved by Congress, and this has greatly politicized the process. Opponents of public television believe that specialized commercial cable services, such as Bravo, the Discovery Channel, and the Learning Channel, have usurped the originally intended function of PBS and that taxpayer expense cannot therefore be justified. Proponents argue the necessity of protecting at least some small piece of American teleculture from raw market forces. Cynics point to the domination of noncommercial TV by commercial interests (which are today audiovisually identified on the air, contrary to earlier policy) and dismiss the controversy as moot.

Up until the late 1970s television was strictly a mass medium. The three networks, working with their radio broadcasting model, had collectively assembled an audience in the hundreds of millions, with virtually no regard for traditional cultural determinants, such as class, education, religion, or ethnicity. It was not unusual during the broadcast era for the chief executive officer of a large corporation and the person who swept the office both to have seen the same dramatic presentation or newscast on television. There had never been anything like it in history.

Two mass diffusions of technology would occur, however, that would end this phenomenon by broadening the definition of the medium beyond the limits of over-the-air transmission: the spread of closed-circuit cable TV subscription; and the availability of self-programmable home video devices, especially the VCR. Whereas it had been once taken for granted that television was a form of broadcasting, in the 1980s it became apparent that broadcasting would be but one form of television. A primitive implementation of cable TV, known as Community Antenna Television (CATV), had been in operation almost since television had first gone on the air. In small- and medium-sized inland regions, especially in the noncoastal areas of the Northeast, large industrial antennas were built that could pull in TV signals from New York, Philadelphia, and other cities large enough to sustain nonnetwork independent stations and noncommercial educational stations. Companies were granted municipal utility franchises to run lines from these antennas over or under city streets to the homes of subscribers. As a result the number of available stations in cities such as Syracuse, New York, and Scranton, Pennsylvania, rose from three or four to six or seven for those viewers willing to pay a monthly fee.

Beginning in the 1970s this once tranquil business experienced an extraordinary boom. It was given its first great boost in 1975 when the publishing company Time, Inc. (a forerunner of media giant Time-Warner) established a nonbroadcast, pay-TV channel, Home Box Office (HBO). The service was offered to existing cable systems, which in turn charged subscribers an extra premium above the basic monthly price they had been paying. HBO's narrowcasts of feature films and spectacular sporting events, such as championship boxing matches, were presented without commercial interruption, an unprecedented viewing option for popular television.

The availability of communication satellites for the relay of signals turned small mom-and-pop CATV operations into satellite ground stations and abruptly ended the scarcity of television channels that had been artificially imposed by the old broadcasting companies. By the end of the 1970s, entirely new forms of television were being offered: an all-news channel (CNN); an all-sports channel (ESPN); a television channel aimed specifically at children (Nickelodeon); and so on. The great mass audience that had been built by the broadcasting companies over the preceding half century was gradually chopped back up into its demographic components.

The small cities and rural areas that already had CATV systems in place were the first to receive the new cable channels. Given the fact that these viewers were used to paying for TV, it was not surprising that improvements in service were welcomed by most viewers, as indicated by their willingness to pay higher subscription rates. However, it remained a matter of speculation as to whether or not the populations of major metropolitan areas would actually pay for television, which they had always taken for granted as free. Thus the nation's largest cities were among the last to be wired for cable TV. However, wherever cable went, it was embraced in no uncertain terms by the majority of viewers. Viewers who were unable to get cable TV, or who did not want to pay subscription fees to the cable company, set up their own home satellite dishes. By the end of the twentieth century, a typical American cable subscriber had about eighty available channels to choose from, with promises of much more from the industry.

When asked about this phenomenon Thomas S. Rogers, president of NBC Cable and a founding figure of such channels as CNBC and MSNBC, replied, “I don't think you can ever underestimate the American public's desire for more video choices. That appetite seems to expand. It's peculiar in some respects, because the number of channels that people actually watch is no more than ten or twelve, even as the number of channels available to them may expand well beyond that.”

The other major change in televiewing that took place during the 1980s was the mass diffusion of the VCR. This device, originally known as the video tape recorder (VTR), was developed by the Ampex Corporation during the 1950s, mainly as a way to record live television programs for rebroadcast in the western time zones. Early VTRs cost tens of thousands of dollars per unit, and thus use was limited to industrial purposes. The first on-the-air broadcast of videotape occurred in 1957 as part of CBS's live coverage of the Kentucky Derby. Just minutes after the race ended, it was shown again to an astonished national television audience.

Several Japanese corporations, especially Sony Corporation and Matsushita Electric, set out to devise videotape systems that were cheap enough to mass-produce for home users. RCA, which had dominated broadcasting technology since the radio era, refused to become involved in this competition, instead putting all its efforts into a home disk system, which did not have the capability of taping on-air programs. Broadcasters even attempted to sue VCR manufacturers for encouraging theft of their product, but court decisions went against them. This miscalculation led to a half-billion dollar loss by RCA and its corporate takeover by General Electric, a diversified company which, among other things, manufactured VCRs.

By the late 1970s both Sony's Betacam and Matsushita's video home system (VHS) were on the market and, in a matter of a few years, the VCR had grown into a common household appliance, with the cheaper VHS type eventually emerging as the standard operating system. At first the VCR tended to attract buyers who wanted to view foreign-language films, pornography, and other forms of entertainment not shown on broadcast television. But gradually a market was recognized for videotapes of mainstream films; by the 1980s videotape rentals of Hollywood feature films were outgrossing their box office takes.

The TV set had now become the videoscreen, and it was put to use with an increasing number of appliances. For many families home camcorders became the medium of domestic record, with videotape cassettes replacing photograph albums and home movies. Video games migrated from arcades to home screens, thus introducing a measure of interactivity to a medium that had always been castigated for encouraging passivity. And finally, if looking at a videoscreen is what is meant by watching television, then the home computer must be counted as a video appliance as well. The CD-ROM is perhaps the personal computer (PC) software that most closely resembles earlier television programming. But Internet surfing pushed television into an entirely new set of uses, turning what had once been a downstream transmission system into an interactive communication system capable of carrying not only messages but instantaneous dialogues, commercial transactions, and spontaneous social activities between disparate points all over the globe.

Early on, television proved that it could bring drama home from the theater, movies from the cinema, and sports from the arena. As it developed further it proved it could remove politics from the town square, religion from the house of worship, education from the classroom, music from the concert hall, and so on. Enthusiasts point to the fact that the video screen has made life convenient and put the individual into a position of greater control by eliminating the burden of transportation from so many activities. Critics bemoan the loneliness of a life increasingly devoid of social contact. Enthusiasts credit television with democratizing access to the arts and information. Critics blame TV for compromising the arts and creating an information overload that makes most of what is said meaningless. Enthusiasts foresee the strengthening of positive cultural identities in a multiplicity of channels serving an increasing number of demographic communities. Critics foresee a nation devoid of all national identity save the oceanic bond consumers feel with others while watching television.