He then was appointed professor of physics at New York’s Columbia University. Being there, he discovered one incredible thing: uranium neutrons were emitted into fissioning uranium, they could split off atoms and set off a chain reaction thus releasing enormous amounts of energy. This discovery led to the very first controlled nuclear chain reaction in 1942. Albert Einstien and Enric Fermi both fled to the United States and agreed upon the dangers of atomic technology in the hands of the Axis powers. Enrico traveled to Washington to express their concerns to government officials. However, few shared his concerns. Einstein wrote a letter to President Roosevelt urging the development of an atomic research program. Roosevelt saw neither the necessity nor the utility for such a project. However he agreed to proceed slowly. In late 1941, the American effort to design and build an Atomic bomb received its code name — the Manhattan