Answer:
The South Carolina low country, as well as the North Carolina, Virginia and Georgia lowcountry, helped prosper the economy of the colony, and then the state, because it is a very fertile region where large plantations of cash crops like rice, tobacco and indigo could be planted. This led to the formation of a plantation economy based on slave labor.
Besides, the low country has many riverways, and easy access to the sea, meaning that the cash crops could be readily shipped to Europe, in order to be sold.