Which energy source does the united states have in abundant supply

this is ur answer hope it helps .

In 2015, 33.2% of U.S. electricity came from coal— roughly equal to natural gas (32.7%), but greater than nuclear power (20%) or renewable energy sources (13%). There is an abundant supply of coal in the United States and it's a relatively inexpensive energy source so this  is ur answer

separation of church and state? not sure what you mean.