This is discussion archived from a time before the current discussion method was installed.
Morgan Wick: A brief history of the (TV) networks (though by necessity touching on radio history as well). Feel free to merge it into the article, or edit it for accuracy or other legitimate purposes, as you wish.
Way back, in days of yore (the 20s and 30s), there were two major suppliers of radio programming: CBS and RCA (through its NBC brand), broadcasting on three major nationwide radio networks: CBS, NBC Red, and NBC Blue. (Think of BBC 1 and 2 in the UK, only NBC was never owned by the government.) Both of these two radio companies knew that the future lay in television and worked their asses off in a race to see who could develop television further. It was NBC that provided a very early demonstration of the potential of television at the 1939 World's Fair.
That came to a halt when World War II hit, as all resources had to be redirected to the war effort, and most of the few TV stations in existence shut down. Still, television history marched on, and NBC performed an early experiment in linking two stations to simulcast the same programming in 1943. That same year, as a result of a 1940 FCC report on antitrust concerns, NBC sold its Blue network, which became ABC. Allen B. Du Mont, a seller of television sets, launched what could be considered the first true television network in 1945, to provide something for his sets to show. ABC wouldn't start its own TV network until 1948.
After World War II, TV made up for lost time so fast the FCC imposed a licence freeze in 1948, which was hard on Du Mont and ABC, who couldn't compete with the two giants of radio and now television, NBC and CBS. The FCC finally released the licence freeze by creating the UHF band but giving it almost no support whatsoever, initially imposing no requirement that T Vs be equipped with UHF tuners, and reserving VHF channels for public television (PBS) stations. Because of the technical details of the VHF band, Du Mont and ABC were de facto forced onto UHF stations in most markets if they wanted full clearance of their schedules.
(Incidentially, the article may want to mention that, partly because the US is so big, individual stations/affiliates are far more independent than in, say, Europe, at least in theory.)
Du Mont had two crippling problems: it didn't have a radio network for brand recognition and cross-promotion, and it was partly owned by Paramount. Paramount, like most movie studios, hated television and sought to kill it, and Du Mont in particular. For example, FCC regulations at the time capped station ownership at five; Paramount already owned two, so the FCC capped Du Mont at three and Paramount wouldn't put Du Mont programming on its own stations. Despite this, it still was a strong third place over ABC until ABC merged with United Paramount Theatres (which I think, but I'm not 100% sure, was Paramount's former theater chain, following the Supreme Court decision that barred studios from owning theaters) and got a boatload of money. After a proposed merger fell through, Du Mont went off the air. ABC might have followed suit were it not for the FCC taking two more actions in the 60s: rearrange the allocation table to give ABC more VHF stations, and finally require new T Vs to come with UHF tuners.
Several more groups tried unsuccessfully to start networks in the 60s and 70s, but all failed until Fox launched in the 80s. Fox succeeded partly by overturning conventional wisdom in almost every way possible, partly by programming too few hours to meet the FCC definition of a network, and partly by being backed by Rupert Murdoch's billions. This explains why Fox only programs sports and prime time, doesn't program the 10pm ET/PT hour, and doesn't do its own news despite being co-owned with Fox News, apart from the Fox News Sunday public affairs program. Most of the strong independents were lapped up in the Fox network, but that didn't stop UPN and the WB from launching in 1995, and folding in 2006 to create the CW. Fox, which by then owned the major UPN stations (it's a long story), then created My Network TV for the bridesmaids of the CW merger. Ironically, entering the 2008-09 season the CW itself is rumored to be on its last legs and My Network TV could be energized by the introduction of WWE Smackdown.
Cable television was invented in 1948 to deliver TV signals to remote areas but it wasn't until the 1970s that networks specifically geared to cable consumption started popping up, and became so popular that people practically living at the foot of TV transmitters flocked to cable (and satellite) in droves. As a result, the coming transition to digital television, truth be told, won't have much of an effect on most people since they don't pick up their TV signals with a rabbit-ears.
</Morgan Wick>
