George Braxton Pegram (October 24, 1876 - August 12, 1958) was a US physicist who played a key role in the technical administration of the Manhattan Project.

Pegram was born Trinity, North Carolina, one of the five children of William Howell Pegram, professor of chemistry at Trinity College, and Emma, daughter of Rev. Braxton Craven, the college's president. His upbringing in the academic atmosphere of the campus left him with an appetite for careful methodical work and an inherent diplomacy.

Pegram graduated from Trinity in 1895 and taught high school before becoming a teaching assistant in physics at Columbia University in 1900. He was to spend the rest of his working life at Columbia, taking his doctorate in 1903 and becoming a full professor in 1918. His administrative career began as early as 1913 when he became the department's executive officer. By 1918, he was Dean of the Faculty of Applied Sciences but he resigned in 1930 to relaunch his research activities, performing many meticulous measurements on the properties of neutrons with John R. Dunning.

Returning to administration in 1936, as Dean and Chair of Columbia's physics department, Pegram was instrumental in bringing Enrico Fermi to the US to escape the Fascist regime of his native Italy. In 1940 he brokered a meeting between Fermi and the US Navy at which the prospect of an atomic bomb was raised with the military for the first time.

The Columbia physics department was home to many of the key technologies required for the bomb project and Pegram and his colleague Harold C. Urey soon found themselves on Vannevar Bush's S-1 uranium commmittee coordinating all technical research. In autumn 1941, Pegram and Urey led a diplomatic mission to England to establish co-operation on development of the atomic bomb.

Pegram died in Swarthmore, Pennsylvania.

Bibliography

• Embrey, L. A. (1970) Biographical Memoirs, National Academy of Sciences vol. 41, pp357-407