Fehsenfeld enrolled in Purdue at the age of 17 but later enlisted in the U.S. Army Air Cops on his 18th birthday. After four months, he was later called up and trained to fly P-47 Thunderbolts. Fehsenfeld flew 86 missions in Europe — most in the P-51 Mustang — in over a little more than a year. He was awarded the Air Medal with three silver clusters and the Silver Star.

Fehsenfeld returned to Purdue after the war, receiving a bachelor’s degree in mechanical engineering in 1948.

After graduation, he found success with the expansion of The Heritage Group (THG), which operates the country’s largest privately held environmental company. The companies of THG are also involved in highway construction, aggregate production, chemical production, oil refining, and petroleum marketing, as well as crude oil and natural gas production.

He was a loyal supporter of Purdue University through numerous contributions over the years, including the establishment of the Fehsenfeld Family Head of EEE.

“The generosity of Fred and Barbara Fehsenfeld and the rest of the Fehsenfeld family have made a world of difference to EEE in providing assistance to students, faculty, and program development,” noted John W. Sutherland, the Fehsenfeld Family Head of EEE. “I loved spending time with Fred,” added Sutherland. “He was passionate about seeking creative ideas that could be economically successful and preserve the environment for future generations.”

Fehsenfeld also received an honorary doctorate in civil engineering from Purdue.