Manhattan Project Scientists: Edwin Mattison McMillan

A man in a suit stands in front of scientific equipment.
Physicists Edwin McMillan and Phillip Abelson produced element 93, neptunium.


Quick Facts
Artificially created the first transuranium element and later worked at Los Alamos
Place of Birth:
Redondo Beach, CA
Date of Birth:
September 18, 1907
Place of Death:
El Cerrito, CA
Date of Death:
September 7, 1991
Place of Burial:
El Cerrito, CA
Cemetery Name:
Sunset View Cemetery

Born in California in 1907, Edwin McMillan received his undergraduate degree from Caltech in 1928 and his PhD in chemistry from Princeton University in 1932. In 1940, McMillan and colleague Phillip Abelson produced element 93 which they named neptunium. Produced by bombarding uranium 235 with neutrons, neptunium was the first artificially-created transuranium element. In 1941, chemist Glenn Seaborg, along with McMillan and several others, produced element 94 which Seaborg named plutonium, following McMillan naming element 93 after a planet. 

In 1942, McMillan moved to Los Alamos to research implosion methods for the Manhattan Project, living on the famous “Bathtub Row” during his tenure. After the war, McMillan won the Nobel Prize in Chemistry in 1951 for his work on transuranium elements, became a member of the General Advisory Committee to the Atomic Energy Commission, and served as director of the Lawrence Radiation Laboratory from 1958 to 1973. Edwin McMillan died in California in 1991.

Manhattan Project National Historical Park

Last updated: January 11, 2023