During the summers of 1931, 1932, and 1933, Arlinghaus taught history classes at Xavier University as a part-time instructor. On June 22, 1933, he signed a contract to begin a position as a full-time instructor in history at the University of Detroit (a Jesuit university). He remained at the University of Detroit throughout his career, rising through professorial ranks to full professor in 1947. In 1950 he became director of the University of Detroits's summer session and evening division. In 1957, he took charge of the newly organized “TV College” (which he had helped to promote as early as 1954) which offered credit courses on local public television affiliates. In addition, he performed the usual duties of teaching, research/publications, and lectures to outside groups on various historical and international affairs topics. From 1960 to 1964 he was the associate dean of the College of Arts and Sciences, and from 1964 to 1968, the vice president for student affairs. In April, 1968, after 35 years of service at the University of Detroit, he was named distinguished professor of history and also the University of Detroit's first university professor. He retired in 1969, but in 1977 he was appointed vice chairman of the Centennial Executive Committee and chairman of the Program Policy Committee for the Centennial Celebration of the University of Detroit.
