The correct answer is Many southern states prohibited the importation of slaves from abroad
Black slavery was implanted during the 17th century and intensified between the years 1700 and 1822, mainly due to the great growth of the slave trade. The height of the influx of black slaves can be found between 1701 and 1810, when 1,891,400 Africans were landed in colonial ports.
The history of slavery (or slavery) in the United States begins in the 17th century, when slave practices similar to those used by the Spanish and Portuguese in colonies in Latin America. The year 1820, for example, is important because on March 2 a compromise was signed that would temporarily calm the differences on the issue of slavery. As a result of this commitment, a new anti-slavery state is inaugurated. Maine would result from the separation of Massachusetts and sought a counterpoint to Missouri. Moreover, it was agreed that the future states that were created in old Louisiânia would be slavery or abolitionists according to their location to the south or north of the parallel 36 ° 30 ', southern border of Missouri. This compromise eases tensions for three decades. However, the divergences in economic and political interests between the North and the South end up making them resurface more alive than ever. In fact, slavery ended only in 1863, with the Abraham Lincoln Emancipation Proclamation, carried out during the American Civil War.