Answer: Use of state militia to quell insurrection.
Explanation:
In acting quickly to supress an insurrection that threatened the unity of the United States by the use of state militia, President Washington set a precedent that would eventually become law with the Insurrection Act.
By this precedent, Presidents are empowered to raise state militias to quell rebellion if normal civilian judicial procedure fails and after they have ordered the people involved to disperse.
This precedent has been used by quite a number of presidents including Ulysses Grant, John Kennedy and Dwight Eisenhower as they attempted to enforce laws calling for equality.
The Persians were unable to cross the mountains
The correct answer to this open question is the following.
I consider that the Second World War really ended, and differences between allies grew to enter into another facet of an international conflict we know as the Cold War.
We can find some similitudes in the primary conflicts of the two wars, however, the political and economic interests of the United States and the Soviet Union clashed during this period of the Cold War.
After World War II, Soviet Union leader Joseph Stalin was not satisfied with the agreements that resulted from the Yalta Conference. This initiated a series of conflicts and differences with the United States. Both powerful countries aspired to influence and control the world.
The Korean War, Cuban Missile Crisis, the Vietnam War, and the Watergate scandal were all key events that took place during the Cold War era.