Chicago's oldest call letters WBKB (Zenith's WTZR, although older do not count as the calls were never used) had been first used in 1943.   Launched in 1940 as experimental W9XBK by John Balaban and Capt. Bill Eddy of Paramount's Balaban & Katz Theaters movie house chain, the station found itself a unwitting participant in a anti-trust legal struggle between Paramount and the U.S. Government regarding the movie giant's involvement in film production, movie house chains and local television station ownership.  The end result being United Paramount Theaters, a separate company, which would merge with the financially strapped ABC-TV network in 1953.  Only allowed one station per market (the merger gave ABC two- WENR-TV on channel 7 and Paramount's WBKB on channel 4), ABC sold the channel 4 license to CBS and moved the WBKB call letters to channel 7 replacing the original WENR-TV.  In 1968, the station became WLS-TV.  The circle 7 logo is one of the most familiar and enduring American television station logos.  It is used on all the channel 7 owned and operated ABC stations.


Arguably Chicago's most familiar call letters, WGN, were brought to television in 1948 with the debut of the Tribune's new station on channel 9.  Known through most of it's history as a local independent, the station was briefly affiliated with CBS (sharing some of the network's offerings with rival WBKB) and until 1956, it was the local DuMont Network affiliate, giving the doomed first television network one of its few VHF stations.  The station would become synonymous with quality children's programming in the late 50s to the 80s when it would gradually shift its emphasis to news programs and syndicated reruns.  In 1995, it became a network affiliate once more when it became one of the nation's first affiliates of the new WB Network.   WTTW began in 1955 as Chicago's first educational TV station.  On the air with equipment donated by Zenith's W9XZV, the station would become a leader in public broadcasting and a fine example of what some early opponents of commercial television wished the broadcast industry had become.

Beauty pageants, comedians, movies,  cooking shows, audience participation, and children's programming filled the Chicago television airwaves in the late 40s and early 50s over the city's four stations, WBKB channel 4, WNBQ channel 5, WENR-TV channel 7, and WGN-TV channel 9.