Jackson held academic appointments successively at McGill University, thanks to Philip Russell Wallace, a prominent Canadian theoretical physicist, (January 1950 – 1957); then the University of Illinois at Urbana–Champaign (1957–1967); and finally the University of California, Berkeley (1967–1995). At McGill, he was Assistant and Associate Professor of Mathematics; at Illinois and Berkeley, he was in the Physics Departments. At the latter, he held appointments on campus and at the Lawrence Berkeley National Laboratory. After retiring from teaching in 1993, he continued to be active at LBNL.