Well the federal government is under 3 branches of government the legislative,Judicial, and executive.
Union soldiers were fighting for the freedom of slaves and reuniting the states. Confederate soldiers fought for protecting the confederacy. Yes, it did change over the war.
The New World order was a foreign policy stance that advocates multilateral engagement for the good and protection of an allied Country.
As with any system, there will be an expansion of a population that is only halted by the mechanisms of the system being overly stressed and unable to maintain a population over a certain level or threshold. It is natural to fight for resources in a given system. The European population settled and increased, more resources were needed, land, water, food and supplies. The Europeans fought to maintain and increase the people with whom they associated. And unfortunately a prevalent thought at the time, was the Indians were a "savage other", whose lives were not as valuable and so the Europeans eventually destroyed them.