Part 1 of Essay
We the People of the United States, in order to form a more perfect union, establish justice, insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity, do ordain and establish this Constitution for the United States of Amer ....

Part 2 of Essay
.... about this doctrine is that it does a clever job of dividing certain powers between the state and federal governments.  Monetary units, for example, are issued exclusively by the federal government.  This is not only more convenient for traveling purposes, but also allows for a more 'united' spirit.  People in California can easily view a commercial for a product affiliated with New York without having to translate the cost or watch the television screen scroll down 50 different prices.  The Stock Market ....