Fission Energy and War

Neutron induced fission reactions release energy and neutrons, scientists discovered.
The amount of energy in fission reactions is alarmingly large and the liberation of neutrons in the fission process gives the possibility of an explosive chain reaction.
Scientists fear Hitler to use nuclear energy for war.
European scientists with ethnic backgrounds other than German felt threatened, and they came to the U.S.
Ã Leo Szilard, Eugene Wigner, and Edward Teller wanted to unite political force with nuclear power. They composed a letter for Einstein to sign, and brought the letter to the White House, (political power center).
Roosevelt immediately created an Advisory Committee on Uranium, and gave financial assistance to universities engaged in uranium research. The sum of $300,000 (1940's dollars) was immediately allocated to Columbia, Princeton, MIT, Chicago, California, Virginia etc.
The Chicago group worked on uranium, and the California group worked on plutonium. Soon they realized that enriched ²³⁵U or pure ²³⁹Pu would be required for the construction of an atomic bomb.