1August 2, 939, out of great concern for the fate of mankind, Einstein wrote to suggest that the United States must build an atomic bomb before Germany at the request of several other scientists. A letter drafted by others and signed by Einstein wrote:
Madam President:
I read the manuscript of Fermi and szilard's recent research work. This makes me predict that elemental uranium will become a new and important energy source in the near future. Considering this situation, people should be vigilant. When necessary, the government must also act quickly. Therefore, it is my duty to draw your attention that in the near future, it is possible to create a powerful new bomb. To this end, I suggest that you authorize a person you trust to informally contact various government agencies, report all the research to them regularly, and give them advice, especially to ensure the supply of uranium in the United States. At the same time, establish contact with relevant people and enterprise laboratories to speed up the experimental work. ?
As far as I know, Germany has stopped selling its occupied Czech uranium ore. If you notice that the son of the German Foreign Minister works at the Emperor William Institute in Berlin, which is currently conducting the same uranium research as the United States, it is not difficult to understand why Germany is doing this.
(Signed) Einstein
Roosevelt studied Einstein's letter silently in the White House office and began to feel indecisive. But the thought that Germany was stepping up the development of the atomic bomb secretly made up his mind. After a week's comprehensive consideration, he gave this letter a positive answer and issued an instruction to conduct nuclear test research.
I don't know if it is complete.