How did slaves come to North American? how were they treated

The first 19 or so Africans to reach the colonies that England was struggling to establish arrived in Point Comfort, Virginia, near Jamestown, in 1619, brought by British privateers who had seized them from a captured Portuguese slave ship. Colonists do not appear to have made indenture contracts for most Africans.Slaves proved to be economical on large farms where labor-intensive cash crops, such as tobacco, sugar and rice, could be grown. By the end of the American Revolution, slavery became largely unprofitable in the North and was slowly dying out.

Explanation:

i discarded the supernatant and kept the pellet in this part of the experiment because you have to return all unused chemicals into their original containers at the end of each labratory.

explanation:

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.