Before the Atomic Bomb
World War II began in September 1, 1939 and ended in September 2, 1945. In December 7, 1941 Japan attacked the US at an American naval base(Pearl Harbor) in Honolulu Hawaii. The U.S got involved in World War II in December 8, 1941, after the US Congress approved President Roosevelt declaration of war on Japan.
Before the atomic bomb was dropped, President Truman had to make the decision with the help of other leaders, such as, Winston Churchill and Joseph Stalin. He also made the decision with the help of James Byrnes. James Byrnes was Truman's closest foreign policy advisor during 1945.
The first atomic bomb was made during the summer of 1945 and tested in Alamogordo, New Mexico on July 16, 1945. This event was part of the Manhattan Project and was known as "Trinity."
Once the making of the atomic bomb was successful, the United States was ready to begin a war with Japan. Truman had a speech about The Twelve Points were he mentioned that he did not mean to share the topic of the atomic bomb with anyone. The US used posters during WWII to convince the US citizens about using the atomic bomb.
Before the US began a war with Japan, they allied with Russia(Joseph Stalin) and United Kingdom(Winston Churchill). With the help of Russia and the United Kindgom, the US was able to bomb Japan.
Before they could fully attempt dropping the atomic bombs they also operated combat missions starting June 30, 1945 to prepare the pilots and planes for their atomic mission. They dropped bombs on Japanese controlled islands throughout July to practice radar and visual bombing procedures, in addition to dropping pumpkin bombs in Japan, and practice missions with inert Little Boy and Fat Man prototypes.