To mark the 70th anniversary of President Truman’s decision to drop the atomic bomb on Hiroshima and Nagasaki, Japan, in August of 1945—ending the war and ushering in the Nuclear Age—the Harry S Truman Center for Governmental Affairs at UMKC hosted Dr. Sam Walker on April 9, 2015 at the National Archives of Kansas City. Walker addressed a standing-room-only crowd, providing commentary on the options available to President Truman for ending the war in the Pacific Theater and, citing original sources, explained why Truman made the decision to utilize the bomb. Walker is a Distinguished Lecturer with the Organization of American Historians (2013-2016) and an awardee of the Richard W. Leopold Prize for the best book by a government historian, The Road to Yucca Mountain. He was historian for the U.S. Nuclear Regulatory Commission, 1986-2010, and served as Adjunct Professor at Georgetown University, 1992. He has also written and edited numerous books and publications, among them, Prompt and Utter Destruction: Truman and the Use of Atomic Bombs against Japan.