Complex sentence: At Indiana University he was selected four times by IU students as Professor of the Year, and there was not a lecture hall on campus large enough to seat the thousands of students who attempted to sign up for his courses in both history and political science.
Split into simpler sentences: At Indiana University he was selected four times by IU students as Professor of the Year. His lectures were over-attended, and no a lecture hall on campus was found to be large enough to accommodate the thousands of students who wished to sign up for his classes in both History and Political Science.