Erin Moran, who played...

...Joanie on the sitcom Happy Days, died at age 56.

While the show was a truly awful example of 1970s and '80s television, 'twas not ever thus.

People often assume that Happy Days was inspired by the movie American Graffiti, but it actually preceded the 1973 George Lucas film. According to Wikipedia (my emphasis):

The series' pilot was originally shown as "Love and the Television Set," later retitled "Love and the Happy Days" for syndication, a one-episode teleplay on the anthology series "Love, American Style," aired on February 25, 1972. 

"Happy Days" originated during a time of 1950s nostalgic interest as evident in 1970s film, television, and music. Beginning as an unsold pilot filmed in late 1971 called "New Family in Town," with Harold Gould in the role of Howard Cunningham, Marion Ross as Marion, Ron Howard as Richie, Anson Williams as Potsie, Ric Carrott as Charles "Chuck" Cunningham, and Susan Neher as Joanie, Paramount passed on making it into a weekly series, and the pilot was recycled with the title "Love and the Television Set" (later retitled "Love and the Happy Days" for syndication), for presentation on the television anthology series "Love, American Style." In 1972, George Lucas asked to view the pilot to determine if Ron Howard would be suitable to play a teenager in "American Graffiti," then in pre-production. Lucas immediately cast Howard in the film, which became one of the top-grossing films of 1973. Show creator Garry Marshall and ABC recast the unsold pilot to turn "Happy Days" into a series. 

I remember enjoying the pilot when it aired on Love, American Style when I was in eighth grade. (Watch the first few minutes here.) I was very much caught up in the 1950s nostalgia of the time -- why? maybe because the 1970s were in a bit of a hangover from the tumultuous '60s; and/or maybe I wasn't so happy with my own life at the time -- and I devoured things like this episode and American Graffiti. When Happy Days began in January, 1974 I watched it each week religiously. But even though I recall loving that first season, the show quickly devolved into a typically horrible 1970s sitcom beginning in the second year. I stopped watching it, but it's worth noting that not every crummy TV show starts out that way.

P. S. Anson Williams, who played Potsie, was born Anson William Heimlich. His uncle was Dr. Henry Heimlich, namesake of the Heimlich maneuver for treating choking victims.