TV in the U.S. wasn’t national until September 1951. Prior to that, TV was restricted regional relays and early networks in the east and midwest.
A look at unsold pilots aired between 1967 and 1989 on shows like Comedy Playhouse, Just for Laughs, Comedy Time, and CBS Summer Playhouse.
During the mid-1960s the networks experimented with airing serialized TV shows like Peyton Place twice a week (or more) but the fad quickly died out.
A look at unsold pilots aired between 1956 and 1966 on shows like G.E. Summer Originals, Vacation Playhouse, Summer Playhouse, and New Comedy Showcase.
Between 1963 and 1988, only a handful of shows were pulled abruptly without airing a single episode: The Robert Taylor Show, Snip, Mister Dugan, and The Dictator.
Until 1973, several times a year there were no TV ratings. These Nielsen Black Weeks were an opportunity for the networks to air prestige programs.