Leo Szilard was a Jewish HungarianAmerican physicist and inventor. He conceived the nuclear chain reaction in 1933, patented the idea of a nuclear reactor with Enrico Fermi, and in late 1939 wrote the letter for Albert Einsteins signature that resulted in the Manhattan Project that built the atomic bomb.
Leo Spitz was born in Budapest in what was then the Kingdom of Hungary, on February 11, 1898. His middleclass Jewish parents, Louis Spitz, a civil engineer, and Tekla Vidor, raised Le on the Vrosligeti Fasor in Pest. He had two younger siblings, a brother, Bla, born in 1900, and a sister, Rzsi , born in 1901. On October 4, 1900, the family changed its surname from the German Spitz to the Hungarian Szilard, a name that means solid in Hungarian. Despite having a religious background, Szilard became an agnostic. From 1908 to 1916 he attended Reliskola high school in his home town. Showing an early interest in physics and a proficiency in mathematics, in 1916 he won the Etvs Prize, a national prize for mathematics.
Source: Wikipedia