The introduction of the machine gun in the late 19th century revolutionized the conduct of war - gone were the days of leisurely tactics and "civilized" warfare. Though the traditional officer class were at first slow to grasp its potential, it wasn't long before the powerful new weapon made its mark. This study shows how influential the machine gun was in the American Civil War, in creating the European Colonies in Africa, and, above all, in World War I. Beyond this, he shows the equally revolutionary social and moral impact of a weapon that could kill so many, so fast.