The most popular way of "encouraging" another nation to change its government is by staging a coup and instilling an American-backed leader to lead the country.
People had the most power due to the government being afraid they would have too much power (the reason why they left in the first place).
Answer:
The Supremacy Clause of the Constitution of the United States (Article VI, Clause 2), establishes that the Constitution, federal laws made pursuant to it, and treaties made under its authority, constitute the "supreme Law of the Land", and thus take priority over any conflicting state laws.
Answer:
The major physical feature that you would have to cross in order to reach this destination would be the Appalachian Mountains, since these were so large that they discouraged travel to this region for quite some time.