The descriptive epidemiology of violence in the United States is presented. The reasons for the high homicide rates are explored by describing the historical development of violence in Colombia, a developing country with very high homicide rates, and in the United States, which has extraordinarily high homicide rates in comparison with other highly industrialized countries. The historical factors in the United States that contribute to the high violence rates include the genocide of the Indian population, the slave system, and the increasing militarization of the country's economy, ideology, and governmental policy. It is clear that "the United States is a high-violence environment," that it is indeed a violent society.