Edwin Mattison McMillan was an American physicist credited with being the first to produce a transuranium element, neptunium. For this, he shared the 1951 Nobel Prize in Chemistry with Glenn Seaborg. The Nobel Prize in Chemistry 1951, announced November 15, 1951. Edwin M. McMillan and Glenn T. Seaborg, “for their discoveries in the chemistry of the transuranium elements”. Edwin M. McMillan: born 1907, Redondo Beach, CA, USA. Glenn T. Seaborg: born 1912, Ishpeming, MI, USA. Wiki link Wiki link Data: the Nobel Foundation (CC0).