I recently found my copies of Paul Richard's Reviews of this show from 1969. Since they not on the web anywhere as far as I know here it is now.
The above picture is of Walter Hopps taken around the time he was Director of the Corcoran Gallery of Art in Washington D.C.
Click on the photos to enlarge them and double click if necessary to read the above.
The drawing is by Robert Crumb.
Paul Richard Reviewed the Show again about a week later on June 1, 1969. Here is that Review below.
It was too large for my scanner so I had to do it in pieces to get it all in.
The above drawing is by Robert Crumb. Click on it to enlarge it. This is from 1969. Do the freeways in the cities look like this now. I would say Yes.
For all the information and photos I have on this comix art show search my blog for the labels shown below.
Billy Graham / Dope Mystics
Gilbert Shelton
Radical America Komiks
1969
Pen & Ink
19 x 12.5
And click on the link below to see the whole Comic book this drawing comes from which includes stories of Wonder Wart Hog.
The original artwork was large in size. 19 inches by 12.5 inches.