Lt. William A. King was a member of the Army's Counter-intelligence Corps (CIC) and was responsible for conducting background investigations for personnel who had been selected to join the Manhattan Project.
In May 1945, Maj. Gen. Leslie Groves selected King as a courier for the Manhattan Engineer District. King was responsible for hand-carrying the plutonium core of the Fat Man bomb from Los Alamos to Tinian Island. On August 10, 1945, the day after the Nagasaki mission, he was again ordered from Washington, DC to San Francisco to accompany a second core to Tinian. Hours prior to his leaving San Francisco for Tinian, he was notified that the Japanese had surrendered.
In October 1945, King returned to Washington DC and received compliments from General Groves. He was then reassigned as Post Intelligence Officer at Los Alamos in March 1946. He stayed on as the first civilian employee and Security Branch Chief in the Intelligence and Security programs and later stayed on with the Atomic Energy Commission.
Special thanks to Barbara King, his daughter, for providing us with this information.