The risks associated with environmental and occupational exposures are a topic of enormous concern as industrialized nations face the prospects of aging populations and a growing burden of chronic disease. Because of this courts in the United States are being asked to decide who is responsible for new conditions associated with toxic exposures. In recent years historians have been called into courtrooms to explain to juries when information about the dangers of chemicals and other disease-causing agents were known to companies that made or marketed dangerous products. Some have used their expertise to defend industries against lawsuits by workers and consumers in tobacco, lead, asbestosis. Others, such as the authors of this paper, have testified on behalf of workers and consumers who are seeking damages and redress from polluting companies. This paper looks at this recent development through the lens of two historians who have participated in court cases on behalf of children and workers who have come down with diseases associated with exposures to silica, lead, and plastics. Specifically, we explore the response of industries and other historians to our involvement in these cases. We raise the question: what is the proper role of historians in the courtroom and how do we balance our professional and advocacy roles?