new states may be admitted to the united states only if they are approved by
Admission to the Union The Admission to the Union Clause of the United States Constitution, oftentimes called the New States Clause, and found at Article IV, Section 3, Clause 1, authorizes the Congress to admit new states into the United States beyond the thirteen already in existence at the time the Constitution went into effect.
51st state Voters in Washington, D.C. and Puerto Rico have both voted for statehood in referendums.[2][3] As statehood candidates, their admission to the Union requires Congressional approval with the President's signature.[4]