Honest question from a confused Western Canadian: Do Caucasian Americans not eat fried chicken or watermelon? Personally I love those foods, and as recently as 1923 my family was from Sweden.
Sure they do. But in early 20th century American film especially (and perhaps earlier), and "ethnic jokes", African-Americans expressing love for fried chicken, watermelon, cornbread, and chitlin's (don't ask) were frequently topics played for laughs. One of the Our Gang comedies (short subjects with child actors) from the late 20s or early 30s, had Stymie, a little bald Black boy wearing a derby (given to him by Stan Laurel), rubbing what he thought was a magic lamp and wishing for a watermelon.