U.S. state

In the United States, a state is a constituent political entity, of which there are currently 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sovereignty with the federal government. Due to this shared sovereignty, Americans are citizens both of the federal republic and of the state in which they reside. State citizenship and residency are flexible, and no government approval is required to move between states, except for persons restricted by certain types of court orders (such as paroled convicts and children of divorced spouses who are sharing custody).

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, each with separate and independent powers: executive, legislative, and judicial.

States possess a number of powers and rights under the United States Constitution. States and their citizens are represented in the United States Congress, a bicameral legislature consisting of the Senate and the House of Representatives. Each state is also entitled to select a number of electors (equal to the total number of representatives and senators from that state) to vote in the Electoral College, the body that directly elects the President of the United States. Additionally, each state has the opportunity to ratify constitutional amendments, and, with the consent of Congress, two or more states may enter into interstate compacts with one another. The police power of each state is also recognized.

Historically, the tasks of local law enforcement, public education, public health, regulating intrastate commerce, and local transportation and infrastructure, as well as, local, state, and federal elections have generally been considered primarily state responsibilities, although all of these now have significant federal funding and regulation as well. Over time, the 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.

The Constitution grants to Congress the authority to admit new states into the Union.

States of the United States
The 50 U.S. states, in alphabetical order, along with each state's flag: Alabama

Alaska

Arizona

Arkansas

California

Colorado

Connecticut

Delaware

Florida

Georgia (U.S. state)

Hawaii

Idaho

Illinois

Indiana

Iowa

Kansas

Kentucky

Louisiana

Maine

Maryland

Massachusetts

Michigan

Minnesota

Mississippi

Missouri

Montana

Nebraska

Nevada

New Hampshire

New Jersey

New Mexico

New York

North Carolina

North Dakota

Ohio

Oklahoma

Oregon

Pennsylvania

Rhode Island

South Carolina

South Dakota

Tennessee

Texas

Utah

Vermont

Virginia

Washington

West Virginia

Wisconsin

Wyoming



Governments
States are not mere administrative divisions of the United States, as their powers and responsibilities are not assigned to them from above by federal legislation or federal administrative action or the federal Constitution. Consequently, each of the 50 states reserves the right to organize its individual government in any way (within the broad parameters set by the U.S. Constitution) deemed appropriate by its people, and to exercise all powers of government not delegated to the federal government by the Constitution. A state, unlike the federal government, has un-enumerated police power, that is the right to generally make all necessary laws for the welfare of its people. As a result, while the governments of the various states share many similar features, they often vary greatly with regard to form and substance. No two state governments are identical.

Constitutions
The government of each state is structured in accordance with its individual constitution. Many of these documents are more detailed and more elaborate than their federal counterpart. In practice, each state has adopted a three-branch frame of government: executive, legislative, and judicial (even though doing so has never been required).

Executive
In each state, the chief executive is called the governor, who serves as both head of state and head of government. All governors are chosen by direct election.

Borders
Territorial and new state lines often followed various geographic features (such as rivers or mountain range peaks), and were influenced by settlement or transportation patterns. In the West, relatively arbitrary straight lines following latitude and longitude often prevail, due to the sparseness of settlement west of the Mississippi River.

Once established, most state borders have, with few exceptions, been generally stable. Several of the original states ceded land, over a several year period, to the Federal government, which in turn became the Northwest Territory, Southwest Territory, and Mississippi Territory. Maryland and Virginia ceded land to create the District of Columbia (Virginia's portion was returned).

Regional grouping
States may be grouped in regions; there are many variations and possible groupings. Many are defined in law or regulations by the federal government. For example, the United States Census Bureau defines four statistical regions, with nine divisions. The Census Bureau region definition (Northeast, Midwest, South, and West) is "widely used … for data collection and analysis," and is the most commonly used classification system. Other multi-state regions are unofficial, and defined by geography or cultural affinity rather than by state lines.