Rich vs. Poor! 1920's PLEASE HELP!!!?

Does anyone know anything about how the nation was divided between the rich and poor during the 1920's? I have to write an essay about how in spite of the prosperity of the 1920's, the nation was divided between the rich and poor (as well as other subjects which I have found sources for). If anyone can give me any information or sources (preferably online) pertaining to this topic, it would be greatly appreciated.