Channel 4 signed on October 22, 1957 as KPAC-TV, an NBC affiliate owned by Texas Gulfcoast Television, Inc., itself jointly owned by Port Arthur College, owner of KPAC radio (1250 AM, now KDEI; and 98.5 FM, now KTJM), and the Jefferson Amusement Company. Port Arthur College sold its stake in the station to the Jefferson Amusement Company in 1965; as Port Arthur College retained the radio stations, channel 4 changed its call letters to KJAC-TV (the call letters were derived from the company's name).