Short Answer 
Cotton was the dominant cash crop in South Carolina during the antebellum era, driving economic growth largely through the use of enslaved labor. The link between cotton production and slavery created a system in which enslaved individuals worked under harsh conditions, making slavery crucial to the southern economy as plantation owners relied on maximizing cotton yields for profit.
Step 1: Understanding Cotton’s Role
The major cash crop that significantly impacted the economy of South Carolina was cotton. During the antebellum era, cotton became the dominant commercial crop in the South, driving economic growth. This agricultural boom was primarily fueled by the enslaved labor force, which was essential for cotton cultivation and harvesting.
Step 2: The Link Between Cotton and Slavery
Cotton production in South Carolina directly tied to the institution of slavery. Plantation owners depended on the labor of enslaved people to maximize their cotton yields. The relationship between cotton and slavery created a system where numerous enslaved individuals were forced to work under harsh conditions to meet the high demands of cotton production.
Step 3: Economic Impact of Cotton and Slavery
The wealth generated from cotton sales made slavery an integral part of the southern economy. Plantation owners strategized their harvests based on enslaved population sizes, ensuring high productivity rates. This profit-driven model led to the expansion of slavery, further entrenching the practice in Southern society and its economy.