An industry's legitimacy depends on stakeholders' perceptions and assessments of the appropriateness of its behavior across a wide array of settings. While products and services may be highly valued, and in some cases essential, business externalities serve as a powerful counterforce undermining legitimacy. The work draws on the theory of industrial legitimacy and employs a taxonomy of four different legitimacy sub components; pragmatic, regulative, normative, and cognitive. The paper identifies how externalities affect an industry's legitimacy and the relative contribution of each sub component. The research then empirically tests the theory using the case of the Illinois livestock industry.