January 24, 1950 – Cold War: Klaus Fuchs, German émigré and physicist, walks into London's War Office and confesses to being a Soviet spy: for 7 years, he passed top secret data on U.S. and British nuclear weapons research to the Soviet Union; formally charged February 2.
Klaus Fuchs was just one of the many eccentrics chosen to work on the Manhattan Project. People remembered him as being serious, quiet, and earnest. He was also a spy — whose eventual capture lead to both the Red Scare and the arrest of the Rosenbergs.
February 3, 1950: Klaus Fuchs arrested on spying charges - Klaus Fuchs, a German‐born British scientist is arrested in Great Britain for passing top‐secret information about atom bomb to the Soviet Union.