War II. The station's call letters were later modified to WTMJ-TV (referencing The Milwaukee Journal), which first signed on the air on December 3, 1947, originally broadcasting on VHF channel 3. In addition to being the first commercial television station to sign on the air in Wisconsin, the fourth such station to sign on in the Midwestern United States and the 15th to launch in the United States, WTMJ was also the first station located outside of the Eastern Time Zone to be affiliated with a major broadcast television network. At the time it began operations, there were only 500 television sets in Milwaukee; that number would jump to 2,050 by the following April. The existence of television sets in Milwaukee before WTMJ-TV even debuted was because the city is close enough to Chicago that television stations from that market could be and still are viewable in Milwaukee; therefore, residents in southeastern Wisconsin had access to WBKB-TV (now WBBM-TV), which signed on from Chicago in 1946 as the first commercially licensed television station outside of the Eastern Time Zone. At its official sign-on, it was one of several flagship media properties owned by Journal, which in addition to the Journal newspaper, also owned radio station WTMJ (1020 AM, now at 620 AM). In 1959, these properties were joined by WTMJ-FM (now WKTI at 94.5). WTMJ-TV has been affiliated with NBC since its sign-on, owing to its radio sister's longtime affiliation with the NBC Red Network; although, it also initially carried programming from CBS, ABC and the DuMont Television Network. It lost its secondary affiliation with CBS when WCAN-TV (channel 25, now defunct) signed on in September 1953, and lost access to ABC and DuMont programming when WOKY-TV (channel 19, now CW affiliate WVTV on channel 18) made its debut one month later. WTMJ is the only television station in Milwaukee to have been affiliated with the same network throughout its history, and is currently NBC's second-longest tenured affiliate, behind only KSDK in St. Louis (which signed on as KSD-TV eleven months earlier in January 1947). On July 11, 1953, WTMJ-TV moved to VHF channel 4, in order to alleviate interference with WKZO-TV (now WWMT) in Kalamazoo, Michigan, which is located nearly directly across Lake Michigan. The relocation of the station's channel allocation was a part of the FCC's complete revision of its Table of Channel Assignments, as issued in the