The class system, migration from farms to cities, Social Gospel movement, role of settlement houses and churches provided services to the poor. Between the Civil War and World War I the American cities underwent through dramatic changes in shape, size, and changed in aspects of who was there, and how these individuals were scattered in the city. The driving force behind the urban changes was industrialization and the emergence of industrial slums on the edges of expanding business districts. The slums were assumed to breed illnesses, crimes, intemperance, and immorality. It resulted in the rise of progressive social reformers who developed new methods of helping the poor, who were mostly immigrant communities to be able to adjust to a rapidly changing, increasingly complex urban society.
In this case, any value given up by not choosing to
<span> spend or save the money is the "opportunity cost", because the money </span>could be spent elsewhere. "trade offs" and opportunity costs are very similar though in economics.
