Final answer:
South Carolina changed from being a Proprietary colony to a Royal colony due to the citizens' dissatisfaction with the Lords Proprietors and their desire for government and protection provided by the English Crown.
Step-by-step explanation:
The citizens of South Carolina petitioned to become a Royal Colony in 1719 due to their dissatisfaction with the Lords Proprietors and the ongoing dangers they faced, such as pirate attacks and threats from Indians and the Spanish. As a Royal Colony, South Carolina would receive government and protection from the English Crown. This change occurred after the citizens moved away from the Lords Proprietors and decided to seek the benefits and security offered by the Crown.