A U.S. state (abbreviation o Unitit States state) is ony ane o the 50 federatit states o the Unitit States o Americae that share sovereignty wi the federal govrenment. Acause o this shared sovereignty, an American is a citizen baith o the federal entity an o his or her state o domicile. Fower states uise the offeecial title o commonweel rather than state. State citizenship is flexible an no govrenment approval is required tae move atween states (wi the exception o convicts on parole).
The Unitit States Constitution allocates pouer atween these twa levels o govrenment. Bi ratifyin the Constitution, the fowk transferred certain limited sovereign pouers tae the federal govrenment frae their states. Unner the Tenth Amendment, aw pouers no delegatit tae the U.S. govrenment nor prohibitit tae the states are retained bi the states or the fowk. Historically, the tasks o public safety (in the sense o controllin creeme), public education, public health, transportation, an infrastructur hae generally been considered primarily state responsibilities, although aw o these nou hae significant federal fundin an regulation as well (based lairgely upon the Commerce Clause, the Taxin an Spendin Clause, an the Necessary an Proper Clause o the Constitution).
Ower time, the Constitution haes been amendit, an the interpretation an application o its provisions hae chynged. The general tendency haes been toward centralization an incorporation, wi the federal govrenment playin a muckle lairger role than it once did. There is a continuin debate ower states' richts, which concerns the extent an nature o the states' pouers an sovereignty in relation tae the federal govrenment as well as the richts o individual bodys.
Congress mey admit new states on an equal fuiting wi existin anes; housomeivver, it haes no done so syne 1959. The Constitution is silent on the question o whether states hae the pouer tae unilaterally leave, or secede frae, the Union, but the Supreme Court haes ruled secession tae be unconstitutional, a position driven in pairt bi the ootcome o the American Ceevil War.
- See the Fourteenth Amendment to the United States Constitution.
- Aleksandar Pavković, Peter Radan, Creating New States: Theory and Practice of Secession, p. 222, Ashgate Publishing, Ltd., 2007.
- Texas v. White, 74 U.S. 700 (1868) at Cornell University Law School Supreme Court collection.
Further readin 
- Stein, Mark, How the States Got Their Shapes, New York : Smithsonian Books/Collins, 2008. ISBN 978-0-06-143138-8
Freemit airtins 
- Information aboot Aw States frae UCB Libraries GovPubs
- State Resource Guides, frae the Library o Congress
- Tables wi auries, populations, densities an mair (in order o population)
- Tables with areas, populations, densities and more (alphabetical)
- State an Territorial Govrenments on USA.gov
- StateMaster – statistical database for US States.
- U.S. States: Comparisons, rankins, demographics