At the center of every armed conflict of the 20th Century, the machine gun has been a tool of conquest – and of liberation. Everywhere, it has unleashed consequences its creators never imagined. This is the history of one of the world’s deadliest inventions, a story of technological innovation, industrial revolution, and political power. Three one-hour segments of Machine Gun: history down the barrel of a gun, is a sweeping look at the rise of the American empire.