Coal is the most abundant fossil fuel in the United States. It is a non-renewable resource. This is because it takes millions of years to form. Coal forms underground. It forms where a swamp used to be. When dead plants in a swamp get covered by dirt and water, the energy from the plants gets trapped. Heat and pressure from the layers on top turn the decayed plants into coal. Coal has to be mined. Giant machines remove coal from the ground. Coal is used to make electricity. It is used for industry. It is used to make steel. Coal is also sold to other countries. Miners have to be careful when removing coal from the ground. Mining can destroy land. It .....