Laugh In was a television show on NBC, hosted by Dan Rowan and Dick Martin from 1968 to 1973.
The name Laugh In was a joke on the peacenik's political tool, the Sit In. Others coined Love In and other such terms for peaceful demonstrations against the man.
The show introduced many now-famous comedians to television, and thus a national audience. Goldie Hawn, Lily Tomlin, Ruth Buzzi, Judy Carne, Henry Gibson, Richard Dawson, Arte Johnson, Gary Owens, and Jo Anne Worley, to name a few, were regulars.
Slapstick and joke-telling, on large inexpensive flower-power decorated sets, were the staple, though musical guests like Sonny and Cher would stop in.
No disrespect intended, but Laugh In was for hippies what Hee Haw was for hicks.