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.
Slaves were transported in a massive forced migration over land and by sea from the older slave states to the newer cotton states. In 1850, twenty-five percent of the population of New Orleans, Louisiana, was from the North and ten percent of the population in Mobile, Alabama, was former New Yorkers.