In 1790 there were six slave states; in 1860 there were 15. ·from 1790 until congress banned the importation of slaves from africa in 1808, southerners imported 80,000 africans. ·by 1860 approximately one in three southerners was a slave. which event played the greatest role in creating these conditions in the south during the antebellum era?
a. the northwest ordinance of 1789
b. the dred scott decision of 1857
c. the secession of south carolina in 1860
d. the invention of the cotton gin by eli whitney in 1793