In the earliest days of the Carolina colony (South Carolina split off from North Carolina in 1712), rice was the engine of the colonial economy. Rice also helped to make the colony into a slave society.
Rice became the most important export crop for Carolina (mostly in the part that would become South Carolina) in the late 1600s. Rice was a food that had been cultivated in Africa for a long time. As rice became important to Carolina's economy, more and more slaves were brought over. Slaves who knew how to grow rice were particularly prized. The owners of the rice plantations became the elites of the colony.
Rice, then, caused South Carolina to become a plantation society with planter elites on the top and slaves at the very bottom of the social hierarchy.