Following World War II, the United States began an economic boom that brought unparalleled prosperity to a majority of its citizens and raised Americans' expectations, breeding a belief that most economic and social problems could be solved. Among the crucial themes of this period were the struggle for equality by women and minorities, and the backlash that these struggles evoked; the growth of the suburbs, and the shift in power from the older industrial states and cities of the Northeast and upper Midwest to the South and West; and the belief that the US had the economic and military power to maintain world peace and shape the behavior of other nations.