Bert Tolbert joined the Manhattan Project in 1944 while completing his PhD in Chemistry from the University of California at Berkeley. In April, Tolbert began working for the Radiation Laboratory under E.O. Lawrence and was tasked with separating and enriching small samples of uranium-235 that were used by physicists for various experiments.
Tolbert and his team of chemists eventually developed a machine for separating uranium that was so efficient it was shipped down to Oak Ridge to be tested at the Y-12 Facility. After the War, Tolbert accepted a position as Professor of Chemistry at the University of Colorado in Boulder.