The United States is a **federal presidential constitutional republic**. Power is divided between the national government and the 50 states, with additional authority held by local governments such as counties, municipalities, townships, boroughs, parishes, school districts, and special districts.
## Federal structure - **Executive branch:** Led by the President, who serves as head of state and head of government. - **Legislative branch:** Bicameral Congress, consisting of the Senate and the House of Representatives. - **Judicial branch:** Headed by the Supreme Court, with lower federal courts beneath it.
## Political representation - Each state elects **two U.S. senators**. - House seats are apportioned by population. - Washington, D.C. has a non-voting delegate in the House and participates in presidential elections through the 23rd Amendment. - U.S. territories have varying forms of representation and local self-government.
## Administrative structure - **50 states** with their own constitutions and governments - **Federal district:** Washington, D.C. - **Territories:** Including Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa, and the Northern Mariana Islands - **Tribal governments:** Federally recognized Native nations exercise forms of sovereignty and self-government within the U.S. legal framework
## Public services Public services are delivered across multiple levels of government and include: - Public education - Law enforcement - Fire protection and emergency response - Courts and corrections - Public health - Transportation planning and maintenance - Social services - Utilities regulation - Environmental protection
The current officeholders change over time; for up-to-date leadership, official federal and state government websites are the best source. The U.S. political system is characterized by regular elections, strong judicial review, extensive administrative agencies, and significant debate over federalism, voting access, taxation, civil liberties, and regulatory power.