All of the above. Many people left Eastern Europe for fear of religious persecution (this was around the time of WWII). People from Western Europe left because as America became a "land of opportunity" and capitalist venture, they saw many golden chances to make millions of dollars through the heavy industrialization of the northern states, like Michigan. Political freedoms were also a chance for people to have their voice heard and help others through legislation and politics. Finally, many people (even today) leave their countries to raise their kids in a 'safer' environment than their native countries (this is especially true for people immigrating from Central America, where gang violence is widely present) and in order for their kids to recieve a better education.
A plateau is a raised, flat-surfaced area bound on one or more sides by cliffs or steep slopes.
In the United States and in other western democracies, the "Unwritten Constitution" includes the practice of "issuing currency," since this is not explicitly mentioned in the Constitution.
