Enrico Fermi was an Italian-American physicist who made significant contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics. He is best known for his work on the development of the first nuclear reactor, which led to the first self-sustaining nuclear chain reaction. He was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity. Fermi also made important contributions to the development of the atomic bomb during World War II.