Complex sentence: Before World War II, courses at Radcliffe were segregated by gender from courses at Harvard, however, Kivelson attended Radcliffe in the first class after World War II and the classes did not return to being segregated.
Split into simpler sentences: Before World War II, courses at Radcliffe were segregated by gender from courses at Harvard. However, when Kivelson attended Radcliffe/Harvard in the first class after the war, classes did not return to being segregated.