Historical trauma (HT) is cumulative emotional and psychological wounding over the lifespan and across generations, emanating from massive group trauma experiences; the historical trauma response (HTR) is the constellation of features in reaction to this trauma. The HTR often includes depression, self-destructive behavior, suicidal thoughts and gestures, anxiety, low self-esteem, anger, and difficulty recognizing and expressing emotions. It may include substance abuse, often an attempt to avoid painful feelings through self-medication. Historical unresolved grief is the associated affect that accompanies HTR; this grief may be considered fixated, impaired, delayed, and/or disenfranchised. This article will explain HT theory and the HTR, delineate the features of the HTR and its grounding in the literature, offer specific Native examples of HT and HTR, and will suggest ways to incorporate HT theory in treatment, research and evaluation. The article will conclude with implications for all massively traumatized populations.