Hiroshima, Aug. 6, 1945, and Nagasaki, Aug. 9, 1945. CC BY-SAMore than seventy-five years ago this week, the U.S. military revealed the greatest and best-kept secret of the Allied effort to win World War II. The use of the atomic bomb proved to the world that it was indeed possible to make one. But how had it been possible to keep the secret? And how did U.S. journalists break the news? From New York to Oak Ridge In April of 1945, General Leslie Groves of the U.S. Army approached the managing ed