<p>Michael Tonry has made important contributions to research on sentencing, and especially to research examining racial and ethnic disparities in sentence outcomes. The purpose of this paper is to describe two of the many ways in which Tonry’s ground-breaking research and scholarship transformed the landscape of empirical sentencing research. His influential books and articles documenting why “sentencing matters” encouraged sentencing scholars to evaluate the effects of the sentencing “reforms” enacted during the War on Crime and the War on Drugs, with a focus on determining whether these changes to sentencing policies and practices reduced sentence disparities. Moreover, his critique of the War on Drugs and his argument that the war was being fought primarily in minority communities led to a substantial body of work on unwarranted disparities in sentencing for drug offenses. These are indeed significant contributions.</p>