Edwin McMillan was born in Redondo Beach, California, on September 18, 1907. He received his bachelors degree in physics in 1928 and his masters degree the following year, both from the California Institute of Technology. In 1932 he earned his Ph.D. in physics from Princeton and in the same year became a National Research Council fellow at the University of California at Berkeley, where he worked with Ernest Orlando Lawrence (1901-1958) in the Radiation Laboratory.

One of McMillan's greatest accomplishments was his discovery of neptunium. Also known as element 93, neptunium is the element beyond uranium. The discovery was made in 1940, two years after Enrico Fermi, who had been bombarding uranium with neutrons, mistakenly thought he had produced element 93. Otto Hahn and Fritz Strassman showed that Fermi's analysis of his results was incorrect and that he had instead produced the first nuclear fission reaction.

McMillan, along with scientists throughout the world, became...