<P> The "51st state", in post-1959 American political discourse, is a phrase that refers to areas or locales that are--seriously or facetiously--considered candidates for U.S. statehood, joining the 50 states that presently compose the United States . The phrase has been applied to external territories as well as parts of existing states which would be admitted as separate states in their own right . </P> <P> The phrase "51st state" can be used in a positive sense, meaning that a region or territory is so aligned, supportive, and conducive with the United States, that it is like a U.S. state . It can also be used in a pejorative sense, meaning an area or region is perceived to be under excessive American cultural or military influence or control . In various countries around the world, people who believe their local or national culture has become too Americanized sometimes use the term "51st state" in reference to their own countries . </P> <P> Voters in Washington, D.C. and Puerto Rico have both voted for statehood in referendums . As statehood candidates, their admission to the Union requires Congressional approval with the President's signature . </P> <P> Before Alaska and Hawaii became states of the United States in 1959, the corresponding expression was "the 49th state". </P>

Who has the power to admit new states