Article IV, Section 3, Clause 1 of the United States Constitution authorizes Congress to admit new states into the United States (beyond the thirteen already in existence at the time the Constitution went into effect in 1788). Historically, most new states brought into being by Congress have been established from an organized incorporated territory, created and governed by Congress.^[7] In some cases, an entire territory became a state; in others, some part of a territory became a state. As defined in a 1953 U.S. Senate Committee on Interior and Insular Affairs, the traditionally accepted requirements for statehood are:

• The inhabitants of the proposed new state are imbued with and are sympathetic toward the principles of democracy as exemplified in the American Constitution.
• A majority of the electorate wish for statehood.
• The proposed new state has sufficient population and resources to support state government and carry its share of the cost of Federal Government.^[8]

In most cases, the organized government of a territory made known the sentiment of its population in favor of statehood, usually by referendum. Congress then directed that government to organize a constitutional convention to write a state constitution. Upon acceptance of that constitution by the people of the territory and then by Congress, a joint resolution would be adopted granting statehood. The President would then issue a proclamation announcing the addition of a new state to the Union. While Congress, which has ultimate authority over the admission of new states, has usually followed this procedure, there have been occasions (because of unique, case-specific circumstances) when it did not.^[9]

A simple majority in each House of Congress is required to pass statehood legislation; however, in the United States Senate, the filibuster requires 60 votes to invoke cloture. Some statehood advocacy organizations have called for amending or abolishing the filibuster as a path to achieve statehood.^[10][11] As with other legislation, the President can sign or veto statehood bills that pass, and Congress has the power to override a veto with a two-thirds majority.^[12]