A "Nation State" is a sovereign nation. A group with definite territory that legitimizes it's right to rule by the fact that it exists. A "City State" is like a nation state but smaller, it's a city and it's territories. ... Cities that were only responsible to themselves, they weren't ruled by any higher power.
Answer:
Federalism limits government by creating two sovereign powers—the national government and state governments—thereby restraining the influence of both. Separation of powers imposes internal limits by dividing government against itself, giving different branches separate functions and forcing them to share power.
The First Amendment of the United States Constitution protects the right to freedom of religion and freedom of expression from government interference, not us.