Before Little Boy was dropped on Hiroshima, Leo Szilard at Met Lab in Chicago tried to stop its use. Ironically, Szilard had led atomic bomb research in 1939, but since the threat of a German bomb was over, he started a petition to President Truman against bombing Japan. With 88 signatures on the petition, Szilard circulated copies in Chicago and Oak Ridge, only to have the petition quashed at Los Alamos by theoretical physicist J. Robert Oppenheimer.
When General Leslie Groves learned of the petition, he polled the Met Lab scientists and learned that only 15 percent wanted the bomb used "in the most effective military manner." While 46 percent voted for "military demonstration in Japan to be followed by a new opportunity for surrender before full use of the weapon is employed," somehow the figures were manipulated to suggest that 87 percent of the Met Lab scientists favored some sort of military use. Ultimately, Groves sat on Szilard's petition and the poll until August 1, and then had them filed away. President Truman never saw them.