[2] He was instrumental in Virginia Tech's transition from a small, primarily military, and overwhelmingly white and male technical institute focused on agriculture and engineering that emphasized undergraduate teaching over research or graduate program to, symbolized by its new name, Virginia Polytechnic Institute and State University, a coeducational, racially integrated research university with a thriving college of arts and sciences and burgeoning graduate program.

[4] In 1964, Hahn dropped the requirement for all male students to participate in the Corps of Cadets and severed ties with Radford University, which had been the Women's Division of VPI since 1944.

[5] During this period, Blacksburg was affected by the student anti-war protests with Hahn targeted as a symbol of the bureaucracy in 1970 when considerable disturbance erupted on campus after a group of students and two faculty members protesting U.S. involvement in the Vietnam War interrupted a Corps of Cadets drill, forcing the university to seek an injunction against further disruptive activities by the individuals involved.

Several weeks later after the Kent State shootings a group of students and non-student anti-war protesters seized Williams Hall.

[7] Hahn's tenure as CEO of Georgia Pacific from 1983 to 1993 included the boom years for the paper industry and the hostile takeover of Great Northern Nekoosa by Georgia-Pacific.

[citation needed] Hahn also served as President of Air University (1966–1969) and on the Board of Visitors for Ferrum Junior College (1966–1974).

[2][8] After retiring from Georgia-Pacific in 1993, Hahn returned to Montgomery County, Virginia, where he lived on his farm in the Ellett Valley and raised cattle, sheep, and goats.

[citation needed] In 1976, he received the MIT Corporate Leadership Award and an honorary Doctor of Laws degree from Seton Hall University.