A state of the United States of America is one of the 50 constituent
political entities that shares its sovereignty with the United States
federal government. Due to the shared sovereignty between each state
and the federal government, Americans are citizens of both the federal
republic and of the state in which they reside.[3] State citizenship
and residency are flexible and no government approval is required to
move between states, except for persons covered by certain types of
court orders (e.g., paroled convicts and children of divorced spouses
who are sharing custody).
States range in population from just under 600,000 (Wyoming) to over
38 million (California), and in area from 1,214 square miles (3,140
km2) (Rhode Island) to 663,268 square miles (1,717,860 km2) (Alaska).
Four states use the term commonwealth rather than state in their full
official names.
States are divided into counties or county-equivalents, which may be
assigned some local governmental authority but are not sovereign.
County or county-equivalent structure varies widely by state. State
governments are allocated power by the people (of each respective
state) through their individual constitutions. All are grounded in
republican principles, and each provides for a government, consisting
of three branches: executive, legislative, and judicial.[4]
States possess a number of powers and rights under the United States
Constitution; among them ratifying constitutional amendments.
Historically, the tasks of local law enforcement, public education,
public health, regulating intrastate commerce, and local
transportation and infrastructure have generally been considered
primarily state responsibilities, although all of these now have
significant federal funding and regulation as well. Over time, the
U.S. Constitution has been amended, and the interpretation and
application of its provisions have changed. The general tendency has
been toward centralization and incorporation, with the federal
government playing a much larger role than it once did. There is a
continuing debate over states' rights, which concerns the extent and
nature of the states' powers and sovereignty in relation to the
federal government and the rights of individuals.
States and their residents are represented in the federal Congress, a
bicameral legislature consisting of the Senate and the House of
Representatives. Each state is represented by two Senators, and at
least one Representative, while additional representatives are
distributed among the states in proportion to the most recent
constitutionally mandated decennial census.[5] Each state is also
entitled to select a number of electors to vote in the Electoral
College, the body that elects the President of the United States,
equal to the total of Representatives and Senators from that state.[6]
The Constitution grants to Congress[7] the authority to admit new
states into the Union. Since the establishment of the United States in
1776, the number of states has expanded from the original 13 to 50.
Alaska and Hawaii are the most recent states admitted, both in 1959.
The Constitution is silent on the question of whether states have the
power to secede (withdraw from) from the Union. Shortly after the
Civil War, the U.S. Supreme Court, in Texas v. White, held that a
state cannot unilaterally do so
