The United States has a constitutional federal republic form of government. It is composed of three distinct branches: legislative, executive, and judicial, whose powers are defined and vested by the U.S. Constitution. The legislative branch is Congress (divided into the Senate and House of Representatives), the executive branch is headed by the President, and the judicial branch is made up of the Supreme Court and lower federal courts

. Key features include:

• Federalism: Power is shared between the national (federal) government and the state governments, each with their own constitutions and branches.
• Republicanism: Officials are elected by the people to represent them.
• Separation of Powers: The three branches operate independently but have checks and balances on each other to prevent any one branch from becoming too powerful.
• Constitutional Framework: The U.S. Constitution is the supreme law, outlining the structure, powers, and limits of government.
• Democratic Elements: Citizens vote for representatives and the president (via the Electoral College), ensuring popular participation in governance

In summary, the U.S. government is best described as a constitutional federal republic with democratic principles.