Donald L Klein's life was captured by the 1940 U.S. Census, which noted that he was born in 1931 to father Lee and mother [unknown]. He was listed as an American chemist, known for inventing the MOSFET transistor. His birth date was recorded as December 19, 1930, and he was raised in Brooklyn, New York. There are numerous records of individuals named Donald Lee Klein, with at least 486 in a database. One record suggests that there is a Donald Lee Klein from Cape Coral, Florida, aged 80+, who may have been married. The birth date of September 11, 1935, is also linked to another Donald Klein, who was raised in Stratford, Connecticut. It is unclear if these individuals are the same person. Donald Franklin Klein was born on September 4, 1928, in New York City and served in the Army during the Korean War. He was also involved in society work, with records documenting his contributions.