Here in Connecticut the Big 3 have remained the same since the late 50s.
Channel 3 Hartford - CBS (Previously CBS had been on an O&O on Channel 18)
Channel 8 New Haven - ABC.
Channel 30 New Britain - NBC
Channel 18 Hartford became an independent after CBS sold the station. (Originally Channel 71 a ABC/Dumont Affiliate).
Channel 53 Waterbury was an NBC affiliate for Western Connecticut where they could not receive Channel 30's signal.
Channel 18 was always a throw-away station. In the 60s they were RKO's PAY-TV station. GM at the time was Charles "The Osgoode Files" Osgoode. Later they spent a lot of time on and off the air as an independent station. Eventually the station was bought by Dr. Eugene Scott. In the mid-80s Channel 18 went dark and put up for a distress sale and was bought by Astroline Communications. They were facing stiff competition from 2 new independent stations - Channel 20 in Waterbury (formerly channel 53) and Channel 61 in Hartford. Towards the end they were running infomercials including Jim & Tammy Bakker and Home Shopping Club most of the day,. They went dark in April 1991. Revived in 1997, they showed the Worship Network, the Shop-At-Home Network, and Valuevision Shoppign network. In 2000 they were sold to Entravision and became Univision affiliated WUVN.
http://www.asminor.info/radiojunkie1/whct.html
Channel 61 a new independent station in Hartford signed on in 1984. They eventually became the FOX affiliate, which they remain to this day under ownership of Connecticut One Media d/b/a Tribune.
Channel 20 in Waterbury struggled. They lost the bid for the FOX affiliation to the much more powerful Channel 61. Channel 61 was 5 Million Watts. They ended up showing The Home Shopping Club most of the day. Eventually they were LMA'd by Paramount owned Channel 30 and became the UPN affiliate. Channel 30 even ran a 10PM Newscast on the station. A few years later channel 30 was bought by NBC and Channel 20 ended up being LMA'd by Channel 61 which later purchased it outright. In 2000 they swapped affiliations with Channel 59 in New Haven sending UPN to them and gaining the WB affiliation. Today Channel 20 is WCCT-TV, Connecticut's CW affiliate. (In June of this year they cast-off the 20+ year old WTXX call letters). This fall WCCT-TV took many popular shows from sister station FOX 61 including: Steve Wilkos, Maury Povich, Jerry Springer, Family Guy, and The Simpsons.
Channel 59 in New Haven signed on in 1995 as an independent station WTVU. Initially programming consisted of Coverage of The OJ Trial from KTLA and The Mor Music video shopping channel. Channel 59's programming later consisted of all kinds of old shows including: Matlock, Family Matters, Doogie Howser, I Love Lucy, Beverly Hillbillies. And same-day prime-time repeats of Sally Jessey and Phil Donahue from Channel 8 which was LMAing the station. WB programming which was only on one night a week at the time aired Saturdays. Channel 8 has previously cleared the WB Programming on Wednesdays 12:37AM-2:37AM. Eventually channel 59 became known as WB 59 WBNE. When they swapped affiliations with Channel 20 Channel 59 became known as The X WCTX rather than UPN 59. Eventually they demanded carriage on Cable Channel 9 and around 2005 changed their branding to UPN 9, confusion people who also got WWOR from NYC on cable as they too used the UPN 9 branding. In September 2006 WCTX became the MY Network TV affiliate and took on the MY TV 9 branding, again causing confusion with WWOR which is known as MY 9.
Channel 26 in New London was a low-budget independent station east of the CT River. They struggled for years and several owners went bankrupt. Eventually bought by PAX. (Now ION).
Channel 43 in Bridgeport never had any success. Being a UHF station in an area that could receive programming from VHF stations from NYC. They spent most of their life showing infomercials and shopping. Today they are owned by Multi-Cultural Television and run infomercials 24/7 outside of the E/I programming. They briefly ran RTV programming last year but dropped it due to way too numerous technical problems.
http://www.asminor.info/radiojunkie1/wicc.html