What was the african contribution to the columbian exchange?

The ideas of hammond are most clearly an example of which of the following mid-19th century developments? (5 points) the increasingly liberal nature of slavery after the south enforced stronger slave codes the growing use by northern antislavery activists of moral arguments the increasing number of freed slaves in southern states as a result of gradual emancipation laws the growing tendency of southern slaveholders to use the paternal ethos to justify slavery