Complex sentence: In 1963, Harvard College assumed joint responsibility with Radcliffe over Radcliffe undergraduates, and in 1999 Radcliffe College was dissolved and Harvard assumed full responsibility over the affairs of female undergraduates.
Split into simpler sentences: In 1963, Harvard College assumed joint responsibility with Radcliffe over Radcliffe undergraduates. In 1999 Radcliffe College was dissolved, and Harvard assumed full responsibility over the affairs of female undergraduates.