American television actually started in the late 1930s and early 1940s through test broadcasts in large cities like NY and Los Angeles, typically airing during the evening hours. But early television beared little resemblence to the television that would follow the Second World War. Television broadcasts had fewer lines of resolution, resulting in a blurrier picture. Most early broadcasts were live - usually spoken word interviews or news or telecasts of plays or other live performances which were suited to the heavy equipment required to capture the events.
With the advent of World War 2, television was put on hold in the United States -- radio would remain the most important medium with Americans into the 1950s anyway, and there was no sense utilizing resources for entertainment when there was a war to be won. The fact the country was still in a Depression made the technology unaffordable for most people anyway.
When the war ended, television began to make its impact. Many stations were owned and operated by the same networks that controlled radio: The National Broadcasting Company (NBC) and the Columbia Broadcasting System (CBS) were by far the largest. Mutual Broadcasting, which had importance in radio, stayed away from television. NBC at the time had two networks - the Red Network and the Blue Network. The Red Network featured a lot of entertainment programs, while the Blue Network had more sober current affairs and news programming. An antitrust action would force the split of the two networks into NBC and a new independent company, the American Broadcasting Corporation (ABC). ABC was the last of the big three networks to gain entrance to television, because it had to lease airtime on a number of stations that were part of the DuMont Network. And speaking of DuMont, did you know it was actually the first television network in America? Unfortunately, it didn't survive beyond the 1950s, being America's first network and first failed network!
By the 1950s, the large number of variety shows, usually aired live on the east coast, began to be supplemented with pre-recorded (read that filmed) sitcoms and a whole mess of westerns, which were very popular during this era. West coast viewers saw "kinescoped" versions of live shows.
kinescope: In September 1947, Kodak introduced the Eastman Television Recording Camera, in cooperation with DuMont Laboratories, Inc. and NBC, for recording images from a television screen under the trademark "Kinephoto". Even though their quality left much to be desired, kinescopes were initially the only way to nationally broadcast the live performances of early television from New York or other originating cities to stations not connected to the network. Television programs of all types, from prestigious dramas to regular news shows, were handled in this manner.
As television progressed, and the coaxial cable network carrying programs to the west coast was completed, CBS and NBC instituted a "hot kinescope" process in which shows were filmed (kinescoped) as they aired, rushed to film processing, and then reaired three hours later. CBS filmed the programs on the west coast through microwave links from the east coast, while NBC filmed on the east coast and then rebroadcast the film to the west. The use of this crude and expensive method of time-shifting meant that the television industry’s film consumption eventually surpassed that of all of the Hollywood studios combined.Now let's take a look at some ways networks and stations identified themselves back then, starting with WNBT-TV New York (later WRCA and then WNBC) from the 1940s!