At end of WWII, the allies had officially defeated Nazi Germany when General Alfred Jodi signed the unconditional surrender for all troops on the ninth of May, 1945. Even though the allies main adversary had surrendered, Japan was not giving up until the bitter end. The United States of America had a tough choice at hand, either fight Japan with its own troop and face tremendous casualties, or drop the first nuclear bomb and bring Japan to a swift surrender. Hiroshima was such a pivotal moment in history because the United States of America did in fact decide to drop the first nuclear bomb upon a defiant Japan, on a City named Hiroshima.
Even before the war commenced in 1939 American scientists became increasingly concerned with Nazi Germany and their efforts on nuclear weapon research. Then in 1940, the U.S. government initiated its own development program on atomic weapons. The codenamed "Manhattan Project" was top secret and over the course of the next several years scientist worked on uranium-235 and plutonium-239, the two key elements for nuclear fission1. Then on July 16, 1945, at the Trinity test site in Alamogordo, New Mexico the Manhattan project had its very first successful drop. Although the Trinity test was a success, the allied powers already had defeated Germany in Europe, but Japan, however, announce they would fight until the bitter end despite the very slim chances they had of winning. In late July of 1945, the Allied forces demand Japan to surrender or they would face "prompt and utter distraction" as put forth in the Potsdam Declaration, but Japan's militarist government had rejected it. Then the United states began to way its two options. General Douglas and other top military commanders for the Untied States began to have doubts about the massive invasion, codenamed "Operation Downfall", and they had advised president Harry Truman that this invasion could result in U.