The correct answer is B) 75%
Approximately 75% of the slave population lived on plantations in the South by the mid-19th century.
The US southern states depended so much on agriculture. And for agriculture to be a great business, they needed slavery. Most of the slaves in America were working in the southern plantations by the mid.19th century. Slaves were not considered humans, they were considered property. Southerners enforced slavery of black people by violence and punishment.
