Final answer:
Rice originated in the Pearl River estuary in China and the Carolina low country in the United States. It was cultivated around 6,000-5,000 years ago in China and in the early 1680s in Carolina. The demand for rice in Carolina led to an increase in the slave trade from rice-growing regions of West Africa.
Step-by-step explanation:
Rice originated in two main regions: the Pearl River estuary in what is now China and the Carolina low country in the United States. In China, residents of the Pearl River estuary began cultivating rice in flooded fields called paddies between 6,000 and 5,000 years ago. In the Carolina low country, rice was first planted in the early 1680s, with its introduction possibly originating from Madagascar. Rice production in Carolina quickly expanded, leading to an increased demand for slaves from rice-growing regions of West Africa.