Mostly because it is a Republic, and not a Democracy. There are 50 US States. Most countries are setup as a strong central government and individual authority passed to community levels only as seen proper by the central government.
The United States, as seen by its name, is a collection of 50 individual states, with day to day activities mostly regulated and supported at state level. The US Constitution and Federal Government acts to bind the states and regulate interstate. The 14th Amendment of the US Constitution did put an overseeing authority at Federal level to assure a high level of individual rights protection.
A democracy is an entity of majority rule via voting. The general sense of democracy is a government of the people and by the people, and that still stands. The system is now quite flawed with the power of political parties, major corporations, and wealthy individuals, but that doesn't explain the difference between a Republic and a Democracy.
Each state varies in its exact rules and procedures even if many things are common. Gun/firearm rights and regulation, driving-automobile licencing and registration, taxation methods and amounts, education/school systems, workplace rules and regulations, and many other day to day activity laws and procedures vary by state, and that is by choice of the people in that state. Although the US is joined in some ways, it remains separate states of their own general governance.
The independent nature of states has been there from the founding, and continues today.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.