This essay describes American slavery.

American slavery was an acquisition, one of necessity to ensure the profitability of the colonies. Colonization was a huge expenditure for the respective nations participating in the grab for land in the New World. These nations expected to make their money back and to produce a good clean profit. Once it was obvious to the English that they wouldn't stumble across large deposits of precious metals and riches, they had to find another way to …

…a system of racial hierarchy. The examples lies in the West Indies. But an even stronger argument could be made when examining European nations such as Portugal and Spain. Portugal and Spain had racial hierarchy based upon your amount of African blood. The less African you were, the higher your standing in society was. Therefore, it appears that racial hierarchy was unavoidable, but could have taken on different forms in each of the British colonies.