The United States of America is a federal republic consisting of 50 states (four of which use the term commonwealth rather than state in their full, legal state name), a federal district (where the nation's seat of government—Washington, D.C.—is located), five major territories, and various possessions. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is in the northwestern part of North America (also bordering Canada) and the state of Hawaii is an archipelago in the mid-Pacific. The territories are scattered about the Pacific Ocean and the Caribbean Sea.
States are the primary subdivisions of the United States, and possess a number of powers and rights under the United States Constitution, such as regulating intrastate commerce, running elections, creating local governments, and ratifying constitutional amendments. Each state has its own constitution, grounded in republican principles, and government, consisting of three branches: executive, legislative, and judicial. All states and their residents are represented in the federal Congress, a bicameral legislature consisting of the Senate and the House of Representatives. Each state is represented by two Senators, while Representatives are distributed among the states in proportion to the most recent constitutionally mandated decennial census. Additionally, each state is entitled to select a number of electors to vote in the Electoral College, the body that elects the President of the United States, equal to the total of Representatives and Senators in Congress from that state.Article IV, Section 3, Clause 1 of the Constitution grants to Congress the authority to admit new states into the Union. Since the establishment of the United States in 1776, the number of states has expanded from the original 13 to 50. Each new state has been admitted on an equal footing with the existing states.