The political system of the USA

The United States of America is a federal republic consisting of 50 states, with the District of Columbia as the seat of the national government. Each state has its own government and the state governments follow much the same pattern. The system of the federal, or national, government defined in the Constitution, is based on the separation of powers among three branches: the exectutive, the legislative and the judicial. This system provides a series of checks and balances because each branch is able to limit the power of the others. Before major changes can be made there must be agreement between all the branches.