The federal government of the United States (also known as the United States federal government or the United States government) is the national government of the United States, a federal republic in North America composed of 50 states, a federal district (the District of Columbia, where the government is based), five major self-governing territories, and several island possessions. The federal government is divided into three different departments: the legislative, executive, and judicial branches. The powers of the legislative, executive, and judicial branches are delegated by the United States Constitution to the Congress, the President, and the federal courts, respectively. Acts of Congress further clarify the powers and responsibilities of these branches, including the formation of executive agencies and lower-level courts that are subordinate to the Supreme Court.
'United States of America' is the entire name given to the country by its founders. There is no other name for the country in the Constitution, and it is this name that appears on currency, in treaties, and in court actions in which it is a party (e.g. Charles T. Schenck v. United States). Often, the words "Government of the United States of America" or "United States Government" are used in official documents in order to distinguish between the federal government and the states as a whole. In everyday speech and writing, the terms "Federal Government" and "National Government" are often used interchangeably, with the word "Federal Government" being the most common. The adjectives "Federal" and "National" in the titles of government agencies or programmes often suggest that they are affiliated with the United States federal government (e.g. Federal Bureau of Investigation, National Oceanic and Atmospheric Administration, National Park Service). Because the federal government's headquarters are located in Washington, D.C., the term "Washington" is often used as a metonym to refer to the federal government.
Federalism and republicanism, which determine how power is divided between the federal government and state governments, underpin the United States government's foundation. Since the drafting of the Constitution, controversy has raged over the interpretation and application of these principles, as well as over what powers the federal government should have and how those powers should be used. Some argue for a broad range of federal powers, while others argue for a more restricted role for the federal government in regard to people, states, and other legally recognised institutions.
Although there have been periods of legislative branch dominance (such as the decades immediately following the American Civil War) or when states' rights proponents have succeeded in limiting federal power through legislative action, executive prerogative, or a constitutional interpretation by the courts, the powers of the federal government have generally increased significantly since the American Civil War.