Coal is the primary form of energy used in the United States each day, accounting for one-third of the nation’s total energy production. It is the source of 40% of the electricity generated nation wide. It is by far the most abundant American energy source, accounting for 90% of America’s fossil energy reserves.

In the Industrial Revolution, coal was the fuel that powered the transformation of the United States from an agricultural society into the greatest economic power in the world. Today, it is the direct and indirect source of hundreds of thousands of jobs and billions of dollars in economic impact. Abundant and affordable, coal-fired electricity is the life force of the American economy. It is America’s best friend.
American coal was used at least 1,000 years ago by Hopi Indians in present day Arizona to bake clay pottery. Europeans discovered the mineral in the Illinois River basin in the 1670’s. The first coal mining occurred before the American Revolution, along the Potomac River near the modern border of West Virginia and Maryland.

Technically, coal is not a mineral. Like petroleum and natural gas, coal is a fossil fuel, formed from once living organic materials. Coal was formed from the remains of trees, ferns and other plant life that thrived in the age of dinosaurs, from 400 million to a billion years ago. Each foot of a coal seam represents the accumulation of about 10,000 years of plant remains.Over time, geological processes compressed and altered the plant remains, gradually increasing the carbon content and transforming the material into coal.

Due to varying levels of geologic pressure, coal deposits are of four types: lignite, subbituminous, bituminous and anthracite. Each succeeding type is higher in heating value, as measured by British Thermal Units, or BTU’s. Lignite is found primarily in the southwest and subbituminous in the upper west. Anthracite is limited primarily to certain areas of Pennsylvania. Considering quality and quantity, bituminous coal is the nation’s most valuable coal resource. Bituminous coal is found primarily in the Appalachian states and in the midwest. West Virginia is the most intensive coal state in the U.S.

Western coals were formed 50 to 70 million years ago. Eastern and midwestern coals were formed 200 to 250 million years ago. America is in no danger of running out of coal. Recoverable U.S. reserves total over 290 billion tons, nearly three centuries worth at current production levels.