The article discusses the historical use of coal in the United States for various purposes like iron and steel production and chemical manufacturing. As technology evolved, coal began to be mostly used for generating electricity, making steel, and producing steam. The main focus is on coal combustion, a major way coal is used today. The article also introduces different technologies like combustion, carbonization, gasification, and liquefaction used in coal utilization. It sets the stage for future discussions on cleaner technologies for using coal, such as advanced coal-fired systems, fluidized-bed combustion, and integrated gasification combined cycle technology.