This paper examines the New York City Draft Riots of 1863 using Neil Smelser's Model of Collective Behavior. Neil J. Smelser’s (1962) model of collective behavior is a general theory of emerging social behavior that has been widely applied in many areas including rumors, panics, crowds and social movements. In relation to crowd behavior there have been studies that look at anti-Vietnam war protests and sports riots. However, the model has, to our knowledge, never been applied to major historical riots as opposed to protests. Thus, the purpose of this essay is to show the applicability of the value-added model to the study of an important historical event. Our study focuses on a major riot that took place during the American Civil War- the New York City Draft Riots of 1863. The main goal is to identify those factors that contributed to the actions on the part of the Irish Catholics living in New York City, and their opposition to the war and negative feelings toward the free blacks in the city. The paper examines the structural factors that were present and places them in a historical context.