David Letterman Show in Cresco, Iowa, October 22, 1980

The David Letterman Show's road trip to Cresco, Iowa, taped the previous weekend, aired two days before the final morning show.
At the home of Howard and Jane Goldsworthy, with guest Cloris Leachman and featuring DLS writers Rich Hall and Wil Shriner.
Nearly 35 years before James Corden took his show to a nearby home.
Thanks to C. Bay for the video.