This essay presents a Sephardi physician, J. M. da Costa, who described the Civil War equivalent of Posttraumatic Stress Disorder—Irritable Heart. Da Costa's medical contribution is deemed an origin for the contemporary field of traumatic stress studies. Intergenerational transmission of trauma is an important facet of trauma studies; extensive research exists concerning Holocaust survivors, their children and grandchildren. Second-general children routinely choose helping professions such as medicine in order to master their parents' trauma and to fend off feelings of psychological vulnerability which may lead to assimilation and marrying out. Da Costa personifies such findings. It is suggested that the Marrano experience has not been adequately factored into what it means for Jewish identity and continuity. The concept of tinok she-nishbah, the captured infant, is used metaphorically to frame the problematic discontinuity of identity due to trauma.