Albert Einstein Einstein did not return to Germany. He settled in the United States and became an American citizen in 1940. On the eve of World War II, he endorsed a letter to President Franklin D. Roosevelt alerting him to the potential development of "extremely powerful bombs of a new type" and recommending that the US begin similar research. This eventually led to the Manhattan Project. Einstein supported the Allies, but he generally denounced the idea of using nuclear fission as a weapon. He signed the Russell–Einstein Manifesto with British philosopher Bertrand Russell, which highlighted the danger of nuclear weapons. He was
Hans Albert Einstein father, Albert Einstein, worked as a clerk in the patent office. His father was of German-Jewish descent and his mother, Mileva Marić, Serbian-Orthodox. His younger brother, Eduard Einstein, was born in 1910 and died in 1965. The fate of his older sister, Lieserl Einstein, Albert Einstein's and Mileva Marić's first child, is unknown. Their parents divorced in 1919 after living apart for five years. Einstein followed his mother's and father's footsteps and studied at ETH, the Swiss Federal Institute of Technology, in Zurich, Switzerland. In 1926 he was awarded a diploma in civil engineering. From 1926 to 1930 he worked