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.
On June 1, 1863, three gunboats set out on the Combahee River in South Carolina to begin the dangerous mission. Relying on information Harriet and other scouts received from their sources about the Confederate positions, they began their strategic mission that resulted in over 700 slaves being freed.