Complex sentence: As a primarily New England and Western fraternity, its impulses followed a more progressive course in these matters, while its Southern chapters, themselves not instigating social change, were accomodating to the needs of other chapters where change was more rapid.
Split into simpler sentences: As a primarily New England and Western fraternity, its impulses followed a more progressive course in these matters. Its Southern chapters, themselves not instigating social change, were nevertheless soon accomodating to the needs of other chapters where change was more rapid.