The German-born theoretical physicist, Albert, Einstein, was very well known prior to World War II. He was so well known, that people would stop him on the street to ask him about his theories. It got to the point that Einstein apparently began telling people “Pardon me, I am often mistaken for Professor Einstein.” He had to lie to get away from everyone. He was visiting the U.S. when Hitler assumed power in Germany. Einstein ended up not returning to his country where he’d been a professor in Berlin.
In 1940, he became a citizen of the U.S. and was the one to alert President Roosevelt that Germany might be developing an atomic weapon. He suggested that the U.S. begin research and testing on the matter themselves. Thus, the Manhattan Project was born. Einstein’s wife was his first cousin maternally and his second cousin paternally. They were together for seven years before getting married. He was previously married to another woman whom he cheated on with his second wife. He had three children, but the first one either died or was adopted out. Einstein was a citizen of five different countries throughout his life and was even stateless for a period of 5 years.