The history of energy is defined by the people who discovered its forms and conversions, devised practical ways to harness it, built energy markets that created wealth and jobs, and by those who waged war to increase their control over energy. The giants of science and engineering--Newton, Watt, Curie, Einstein--studied energy. Presidents have struggled to maintain secure and affordable supplies of energy for their citizens, while inventors have designed countless new devices to convert energy from one form to another.