While the energy history of the United States is one of significant change, three fossil fuel sources—petroleum, natural gas, and coal—have made up at least 80% of total U.S. energy consumption for more than 100 years. Recent increases in the domestic production of petroleum liquids and natural gas prompted shifts between the uses of fossil fuels ( largely from coal-fired to natural gas-fired power generation ), but the predominance of these three energy sources is likely to continue into the future. For the first several decades of American history, families used wood (a renewable energy source) as a primary source of energy. Coal became dominant in the late 19th century before being overtaken by petroleum products in the middle of the 20th century, a time when natural gas usage also rose quickly. Since […]