One striking feature of the nation’s energy use is the substantial increase in the quantity consumed, from about 0.3 exajoules (EJ) in 1780 to about 100 EJ in 2007. Energy use in 2000 was nearly ten times as great as it was in 1900, and in 1900 it was eighteen times as great as it was in 1800. The secular increase in energy use was driven by increases in population, economic growth, affluence, and technology. The impacts of major geopolitical and economic events are clearly visible: the Great Depression, major recessions, world wars, the oil price shocks of the 1970s and 1980s, and the COVID-19 pandemic.