Non-renewable resources are resources for which there is a limited supply. The supply comes from the Earth itself and, as it typically takes millions of years to develop, is finite. Non-renewable resources can generally be separated into two main categories; fossil fuels and nuclear fuels.
But there were pockets of the North on the eve of the Revolution where slaves played key roles in the economic and social order: New York City and northern New Jersey, rural Pennsylvania, and the shipping towns of Connecticut and Rhode Island.
Since the Africans seemed to survive longer than the native Indians, the Spanish began to look eastward for a new source of slave labor. In 1518, King Charles V of Spain granted the first license to sell African slaves in the Spanish colonies of America. The West African slave trade had begun. This building on the coast of Africa once was a headquarters for the British slave trade.