Final answer:
Plantation owners topped Southern society due to their significant control over land and enslaved people, affording them considerable wealth, power, and social status.
Step-by-step explanation:
Plantation owners were considered the top of Southern society because they controlled the most land and enslaved people. Wealthy plantation owners formed an elite class with considerable economic and political power, embodied in the cotton kingdom of the South.
Their wealth, largely gained through the labor of enslaved people, afforded them a lifestyle of leisure and social prestige. This group played a crucial role in the politics of the South and the nation, often defending the institution of slavery to maintain and grow their wealth and status.