T. Marshall Hahn Jr., a physicist and college administrator who served as president of Virginia Tech from 1962 to 1974 — years when the mostly male military college grew into a comprehensive university — died May 29 at his home near Blacksburg. He was 89.

University spokesman Albert Raboteau confirmed the death but did not cite the cause.

Dr. Hahn was a politically astute star in academia before he rose to the presidency of what was then Virginia Polytechnic Institute, making him at 36 one of the youngest college leaders in the nation.

He succeeded in quietly transforming the “cow college” in rural Blacksburg into a sprawling university that expanded to include colleges of architecture, arts and sciences, and education. “Primarily under Hahn,” The Washington Post reported in 1967, “VPI has lost its old image as a poor country cousin to the more prestigious University of Virginia.”

As president, Dr. Hahn eliminated the mandatory participation in the Corps of Cadets to open the school to more students. In 1964, the school opened fully to women.

T. Marshall Hahn Jr., shown in 2006, was a physicist and college administrator who served as president of Virginia Tech from 1962 to 1974. (John McCormick/Virginia Tech)

In 1970, the college was renamed Virginia Polytechnic Institute and State University to reflect its growth.

Dr. Hahn served on many state commissions and became one of the state’s most prominent education boosters in the political corridors of Richmond, and for years speculation was rampant that he would make a bid for governor, running on the Democratic ticket. Ultimately, he declined to seek the nomination.

In 1974, Dr. Hahn joined the executive ranks of Atlanta-based Georgia-Pacific, one of the world’s largest makers of paper products. He was named chief executive in 1983 and retired in 1993. During his tenure, he helped lead Georgia-Pacific’s $4.5 billion hostile takeover of Norwalk, Conn.-based paper company Great Northern Nekoosa Corp.

Thomas Marshall Hahn Jr. was born in Lexington, Ky., on Dec. 2, 1926. He graduated from the University of Kentucky in 1945 and received a doctorate in physics from MIT in 1950.

He was a physics professor at the University of Kentucky, chaired the physics department at Virginia Tech and was dean of the College of Arts and Sciences at Kansas State University before being recruited to lead Tech.

His wife, the former Margaret “Peggy” Lee, whom he married in 1948, died in 2009, and their son, William Hahn, died in 1975. Survivors include two daughters, Anne Hahn Hurst and Betty Hahn; and three grandchildren.