Linus Pauling (1901-1994) was an American chemist who won the 1954 Nobel Prize in Chemistry "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances." He revolutionized the study of chemistry, helped found the field of molecular biology, and made important advances in medical research. After winning the Nobel Prize, Pauling focused his attention on peace work, organizing scientists and speaking out against nuclear testing and proliferation, often to great criticism. His peace activism work earned him the 1962 Nobel Peace Prize.