Lorimar Productions was known mostly for family-oriented-&-friendly dramas during the 70's (i.e. The Waltons, Apple's Way). That all changed in April 1978, when they sold CBS a miniseries that ultimately became the first primetime soap opera since Peyton Place signed off more than a decade earlier.
Dallas rewrote the rules for primetime drama. It was one hour, as opposed to Peyton, which was a half-hour, airing 2-3 times a week at its peak. It boasted an ensemble cast led by Jim Davis (ex-Stories of The Century), Barbara Bel Geddes, and Larry Hagman (ex-I Dream of Jeannie), who cemented his icon status with his portrayal of John Ross (J. R.) Ewing, Jr., a morally-challenged weasel who was business first, much to the sorrow of his wife, Sue Ellen (Linda Gray).
Dallas became a national sensation with its season 3 cliffhanger, "Who Shot J. R.?", which had fans speculating all through the summer of 1980. Six years later, the ninth season was written off as an eight month dream sequence of Pamela Barnes Ewing (Victoria Principal), after her husband, Bobby (Patrick Duffy, ex-Man From Atlantis), had supposedly died at the end of the eighth season. Now, you'd think the series had jumped the shark at that point, but Dallas soldiered on for another few years before finally shutting down in 1993.
Nearly 20 years later, Dallas returned, this time on cable's TNT, for 3 seasons. The death of Hagman was the final nail in the coffin for the franchise.
Dallas also birthed a spin-off series, Knots Landing, after Ted Shackleford (Gary Ewing) and Joan Van Ark left the parent series, and Knots had a healthy run of its own. It was also one of the first primetime series for future film star and political bloviator turned game show host Alec Baldwin. Victoria Principal cashed in on her fame in multiple ways. She became a 1-hit wonder on the charts with then-beau Andy Gibb, covering the Everly Brothers' "All I Have to do is Dream", and landed a national bestseller with a series of health & exercise books. I'll bet you anything at all more teenage boys than girls bought The Body Principal when it was released in the early 80's.
Pianist Floyd Cramer covered the show's theme song, and it climbed the country charts. Following is the season 1 intro:
I wasn't much of a soap opera guy, never was, and only tuned in occasionally when channel surfing. No emotional investment, no rating.