In a message to the campus from current President Steve Bahls, he says Tredway first joined the faculty in 1964, served five years as dean, and then 28 years as president.
"His tireless work to build up the faculty and advance the academic program during a period of significant transformation in higher education will forever be recalled with gratitude by those who hold Augustana dear."
During retirement Tredway wrote a history of Augustana, and a biography of Conrad Bergendoff, a previous president.
Arrangements are being made for a campus memorial service.