What role did slavery play in the South in the mid-1800s?

Slavery was so profitable, it sprouted more millionaires per capita in the Mississippi River valley than anywhere in the nation. With cash crops of tobacco, cotton and sugar cane, America's southern states became the economic engine of the burgeoning nation.

Explanation:

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.