<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> <P> Article IV, Clause 3, Section 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 . 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: </P>

When did the us add the 49th state