According to the textbook, by 1860 more than of the slaves in the south worked in cotton production.

By 1860 more than 50% of the slaves in the South worked in cotton production.

EXPLANATION:

South America expanded its wealth and population and became an integral part of an increasing global economy between the 1830's and the beginning of the Civil War in 1861. The introduction of the cotton gin is the major cause for the success of the cotton kingdom.

American cotton production topped to 3 million bales by 1860. Each of the southern planters owned nearly 20 slaves. The rise in the price of the cotton in 19th century leads to rise in the price of the slaves.