List of states and territories of the United States The United States of America is a federal republic consisting of 50 states and one federal district ( Washington , D . C . ) . 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 . Under the tenth amendment to the Constitution , the states can exercise all powers that are not delegated to the federal government . Each state has its own government , consisting of an executive branch , a legislative branch , and a judicial branch . They are all 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 awarded to each state in proportion to their total population . The federal district does not have representatives in the Senate , but has a non - voting delegate in the House . Each state is entitled to electors in the Electoral College , the body that elects the President of the United States , equal to the combined number of senators and representatives that state has in Congress . Congress can admit more states into the United States , but it cannot create a new state from territory of an existing state or merge of two or more states into one without the consent of all states involved . In addition to the 50 states and federal district , the United States has control over fourteen territories . Five of them ( American Samoa , Guam , the Northern Mariana Islands , Puerto Rico , and the U . S . Virgin Islands ) have a permanent , nonmilitary population , while nine of them ( the United States Minor Outlying Islands ) do not . With the exception of Navassa Island , Puerto Rico , and the U . S . Virgin Islands , which are located in the Caribbean , all territories are located in the Pacific Ocean . One territory , Palmyra Atoll , is considered to be incorporated , meaning the full body of the Constitution has been applied to it ; the other territories are unincorporated , meaning the Constitution does not fully apply to them . Ten territories ( the Minor Outlying Islands and American Samoa ) are considered to be unorganized , meaning they have not had an Organic Act enacted by Congress ; the four other territories are organized , meaning they have had an Organic Act has been enacted by Congress . The five inhabited territories each have limited autonomy in addition to having territorial legislatures and governors , but residents cannot vote in federal elections . Out of the 50 states , California is the most populous , with an estimated 38 , 041 , 430 residents as of 2012 ; Wyoming is the least populous , with an estimated 576 , 412 residents . The District of Columbia , with an estimated 632 , 323 residents as of 2012 , has a higher population than the two least populous states ( Wyoming and Vermont ) . The largest state by area is Alaska , encompassing 665 , 384 square miles ( 1 , 723 , 337 square kilometers ) , while the smallest is Rhode Island , encompassing 1 , 545 square miles ( 4 , 002 square kilometers ) . The first state to ratify the current Constitution was Delaware , which it did on December 7 , 1787 , while the newest state is Hawaii , which was admitted to the Union on August 21 , 1959 . The largest territory in terms of both population and size is Puerto Rico , which has 3 , 725 , 789 residents as of the 2010 census and a total area of 5 , 325 square miles ( 13 , 792 square kilometers ) . Map . " Click on a state on the map to go to its main article " Notes . Notes Footnotes