He started as a part-time instructor at University of Iowa in 1951. After obtaining his master's degree in 1952 Hickman worked briefly for Bankers Life Company in Des Moines, Iowa. He then went on to earn his Doctorate from the University of Iowa in 1961. During this time he was working in their mathematics and statistics department and was named a full professor in 1967. He left UI after only five years as a full professor, and in 1972 he went to the University of Wisconsin–Madison. Later (in 1985) he would be named the dean of the School of Business at the University of Wisconsin–Madison. He was dean until 1990 and left the University of Wisconsin–Madison faculty in 1993.