Doonesbury by Garry Trudeau for July 15, 1971
Transcript:
Man: I'm sorry, Mr. Slackmeyer. You know the club doesn't allow negro guests. Calvin: "Negro," did he say "negro?" Mark: I believe he did. It's a reference to your skin hue... Calvin: Why yes, it does appear to be on the dark side... Mark: Let me see... yes, there can be no doubt about it - you're a negro! Calvin: Gee, wait 'till I tell Mom! Mark: Thanks, he didn't know, you see...