Since there appears to be a lack of general cultural knowledge of Henry Gibson and Laugh In, some foggy memories (not least being my own) and deep time historical knowledge of comedians Arte Johnson, the early form of Goldie Hawn, Rowan and Martin themselves, Ruth Buzzi, Jo Anne Worley, and Lily Tomlin 1.0, here’s some material for you.
See how many celebrities you can spot (Henry Gibson is in the very long blooper scene at the end of the first video, at about 8 minutes into the second video with Greer Garson , and elsewhere). Even more interesting, see how may prenumberations you can spot! I see Al Franken. I see The coneheads; I see Lisa Lupner. I see Evening Update. (Lorne Michaels was a staff writer for Laugh-In.)