The origin of the stereotype of black people eating watermelons has
been lost. Some people say that watermelon was first grown in Africa
and then imported to the USA along with the slaves. Others say that the
watermelon provided a clean source of water for the slaves when they
were working in the hot fields. In any event, watermelon became
associated with America's black
slaves--and ultimately became a stereotype, most offensively as a
wonderfully happy black boy in ragged clothes and straw hat eating a
slice of watermelon.