Complex sentence: He attended Brown University (class of 1942) but left because he could only afford one year of tuition; later he made enormous gifts to the university to ensure that no student would ever be forced to leave Brown because of inability to pay again.
Split into simpler sentences: He attended Brown University (class of 1942) but left because he could only afford one year of tuition. Sill, later he made enormous gifts to the university to ensure that no student would ever be forced to leave Brown because of inability to pay again.