About WREX 13WREX began operation on October 1, 1953, as a primary affiliate of CBS. It shared ABC with NBC affiliate WTVO, channel 17 (which signed on five months earlier), and also aired programming from the DuMont Television Network. It was owned by Greater Rockford Television, a group of local businessmen. The station's call letters were selected in honor of Rex N. Caster, the son of station president L.E. Caster. Rex Caster was a First Lieutenant in the United States Army who was killed in France during World War II.
Besides serving its immediate area, WREX attracted viewers early on in its history from parts of the neighboring Madison area. In fact, the two areas still share overlapping coverage among their television stations, especially in Rock County, Wisconsin (technically in the Madison television market), and that market's ABC affiliate, WKOW (channel 27) is a sister station to WREX, assisting with newsgathering in the northern part of the Rockford market. Until Madison's WISC-TV (channel 3) signed on in 1956, WREX was the only VHF station for both the Rockford and Madison areas. This was because Rockford and Madison were sandwiched between markets where other VHF channels were already assigned–Chicago (channels 2, 5, 7, 9, and 11) to the east, Milwaukee (channels 4, 6, 10, and 12) to the northeast, and La Crosse/Eau Claire (channels 8 and 13) to the west.