Designer Bob Mackie, who specialized in elaborate showgirl ensembles is probably best known for his work dressing Cher, as well as his work on The Carol Burnett Show. Mackie created many memorable ensenbles over the show's eleven year run (including the now famous "Went With the Wind" gown, curtain rod and all).
Mackie designed the above pink gown for Madeline Kahn. The gown, though not an accurate depiction of 18th century fashion, at least seems to be inspired by it. The gown utilizes panniers at the sides, and has a row of bows along the front (called échelle).
The gown was used again several years later on Dixie Carter as Julia Sugarbaker in the episode of Designing Women called Blast from the Past. Interetingly, the gown is worn on the show with a hoop skirt instead of panniers in order to make it look more like the gown of a southern belle.
Both The Carol Burnett Show and Designing Women were produced by CBS, so it is most likely that Mackie's creations went on to be used in other CBS productions over the years.
To see the sketch in which this gown appears on The Carol Burnett Show, click here. To see the hilarious speech Julia Sugarbaker gives while dressed in this gown in Desiging Women, click here. And lastly, if you want to see the famous "Went With the Wind" sketch in which Bob Makie's most famous costume creation appears, click here.