Doonesbury by Garry Trudeau for March 23, 1971
Calvin: Please sir, may I sit at your luncheon counter? Waiter: Very funny, fella! You know very well that the 1964 Civil Rights Act stipulates I must serve you...whadda you guys want? Calvin: Please, sir, some chicken and grits, and a big slice of watermelon! Mike: Now cut that out!