George S. Hammond was a chemist at Iowa State University and the California Institute of Technology. Born and raised in Auburn, Maine, he attended nearby Bates College in Lewiston, Maine where he graduated Magna Cum Laude with a B.S. in Chemistry in 1943. He completed his doctorate at Harvard in 1947, under the mentorship of Paul D. Bartlett, and a postdoc at UCLA with Saul Winstein in 1948. Among his awards were the Norris Award in 1968 and the Priestley Medal in 1976 and the National Medal of Science in 1994. Hammond's postulate, also known as the Hammond-Leffler postulate, was based on his 1955 publication.
Hammond was a leader in the field of photochemistry and was widely credited with creating the discipline of organic photochemistry.