Cross next became an assistant professor of civil engineering at Brown University, where he taught for seven years. After a brief return to general engineering practice, he accepted a position as professor of structural engineering at the University of Illinois at Urbana-Champaign, in 1921. At the University of Illinois Hardy Cross developed his moment distribution method. He left Illinois in 1937 to become the chair of the civil engineering department at Yale University, a position from which he retired in 1953.