Ernest O. Lawrence (1901 - 1958)
Born in Canton, South Dakota, he is best known as the inventor of the cyclotron, which won him the Nobel Prize in Physics in 1939. He was involved with the Manhattan Project from nearly the beginning. He was in charge of the electromagnetic separation work at Oak Ridge, Tennessee.
Both the Lawrence Berkeley Laboratory and the Lawrence Livermore National Laboratory were named in his honor. He died on August 27, 1958.