• Federal because power is shared by the local, state, and national governments

• Representative because delegates are elected by the people by free and secret ballot

• Democratic because the people govern themselves
  

• Republic because the U.S. government derives its power from the will of the people

This principle was formalized in 1788 with the ratification of the Constitution. That document - still the supreme law of the United States - became the foundation of a federal government that allowed the several states to act together as one, while protecting the sovereignty of each individual state.

To ensure that no person or group would amass too much power, the founders established a government in which the powers to create, implement, and adjudicate laws were separated. Each branch of government is balanced by powers in the other two coequal branches: The President can veto the laws of the Congress; the Congress confirms or rejects the President's appointments and can remove the President from office in exceptional circumstances; and the justices of the Supreme Court, who can overturn unconstitutional laws, are appointed by the President and confirmed by the Senate.