Harold M. Agnew became the third Laboratory Director in 1970, serving until 1979. Agnew first came to Los Alamos in 1943 as a graduate student, joining the Experimental Physics Division. He participated in the atomic bombing of Hiroshima, flying as a scientific member of the first atomic strike mission.
After completing his graduate work under Enrico Fermi at the University of Chicago, Agnew returned to the Laboratory and worked in weapons development, ultimately becoming head of the Weapon Nuclear Engineering Division in 1964, a position he held until becoming Director in 1970.
Agnew also served as a scientific advisor to NATO and was a member of the General Advisory Committee to the Arms Control and Disarmament Agency. Under Agnew's directorship, Los Alamos developed an underground test containment program, completed the Clinton P. Anderson Meson Physics Facility, acquired the first Cray supercomputer, and trained the first ever class of International Atomic Energy Agency Inspectors.