Relations among the U.S. States

The U.S. Constitution offers a considerable amount of guidance as to the rights, responsibilities, powers, and protections afforded to the states. Article 4 is the part of the Constitution that defines the relationships among states as well as the relationship between the national and state governments. These clauses provide benefits to states' citizens, as well as to state governments themselves. While Article 1, Section 10, stipulates powers states do not have, it also opens the door to states being able to work together on common interests.

The full faith and credit clause is Article 4, Section 1, of the U.S. Constitution, which requires states to recognize and respect the laws and legal decisions of other states, as well as the rights and privileges of the citizens of other states. This provision guarantees that no state's sovereignty can be overruled simply by an individual's crossing a state line. For example, divorce, alimony payments, and child custody are covered in this clause, which ensures that these legal arrangements made in one state cannot be avoided by moving to another state. Because of the full faith and credit clause, a driver from New York can drive through Pennsylvania using a New York state driver's license. However, if that individual moves to Pennsylvania, he or she needs to obtain a Pennsylvania driver's license. For all states, having to license every driver who travels from state to state is burdensome and impractical.

This clause has generated some controversy, however, as some thinkers argue that public policy of a state should not be dictated by contrary policy decisions made by another state. The issue arose when some states began to recognize same-sex marriages and others did not. In 2015, when the U.S. Supreme Court ruled that same-sex marriages must be accepted across the country, it did so on the basis of the due process and equal protection clauses of the 14th Amendment—not on the basis of the full faith and credit clause.

The privileges and immunities clause is Article 4, Section 2, Clause 1, of the U.S. Constitution, which establishes that "the Citizens of each State shall be entitled to all Privileges and Immunities of Citizens" of all the other states. This ensures that the fundamental rights of a citizen cannot be denied simply because that individual comes from a different state. The first clear application of this clause came in Corfield v. Coryell (1823), which Justice Bushrod Washington issued as a circuit court decision. Washington interpreted the clause to apply to fundamental rights, giving such examples as the rights of life, liberty, property ownership, legal action, and travel. The question in this case was whether a New Jersey law that banned nonresidents, such as Mr. Corfield of Delaware, from harvesting clams and oysters in state water, was permissible. Washington ruled that the immunity clause protections did not extend to accessing the resources of another state. Thus, Mr. Corfield had no right to New Jersey's clams and oysters.

Through other cases, the protections of this clause have extended to taxation. States are prohibited from taxing nonresidents at discriminatory rates. In Lunding v. New York Tax Appeals Tribunal (1998), the Supreme Court loosened this requirement somewhat by stating that it was not necessary for the tax burden on residents and nonresidents to be exactly equal but that a state had to show a "substantial reason" for any difference and that the differential treatment had to be based on that reason.

The extradition clause is found in Article 4, Section 2, Clause 2, of the U.S. Constitution, which specifies that an individual who flees from one state to another to escape prosecution or punishment must be extradited, or sent back, to the first state if requested by that state. The language of the clause states that it applies to "Treason, Felony, or other Crime," which courts have interpreted as also extending to misdemeanors, which are minor crimes. However, extradition papers are typically not filed for those accused of minor offenses such as parking tickets or reckless driving. When an alleged criminal is up for extradition, an appeal can be made to the U.S. Supreme Court, which can force a state to comply with an extradition order. Such was the case in a 1998 decision involving Manuel Ortiz, who escaped parole from Ohio to New Mexico. The New Mexico state supreme court denied Ohio's extradition request on the grounds that Ortiz's original conviction had been unjust. A unanimous Supreme Court ruled that the New Mexico court had gone too far; any question of injustice in Ohio had to be tried in the courts of Ohio.

Section 2 originally contained a related clause, Clause 3, which read as follows:

No Person held to Service or Labour in one State, under the Laws thereof, escaping into another, shall, in Consequence of any Law or Regulation therein, be discharged from such Service or Labour, but shall be delivered up on Claim of the Party to whom such Service or Labour shall be due.

In roundabout language, the clause referred to enslaved African Americans and meant that those who managed to escape slavery to a free state could be forcibly returned. Congress enacted a fugitive slave law in 1793, though some northern states erected barriers to full enforcement. This prompted Congress to pass a more draconian measure in 1850 that provoked widespread outrage in the North and helped contribute to the growing sectional tension that led to the outbreak of the Civil War in 1861. The 1850 law was repealed in 1864, during the war. Ratification of the 13th Amendment in 1865, banning slavery, effectively repealed Article 4, Section 2, Clause 3.

James Madison, considered the father of the Constitution because of his central role in its creation, insisted that any new states had to be admitted on an equal footing or they would have no interest in joining the Union. Though that language was not included in the Constitution, acts of admission since Tennessee's in 1796 have included language that the new state is admitted "on an equal footing with the original States in all respects whatever." The U.S. Supreme Court has treated that equality as a constitutional given. One part of Section 3 asserts that no state can be formed from the territory of another state. During the Civil War, however, just such an action was taken, though some effort was made to legitimize the action. When Virginia voted to leave the Union and join the Confederate States of America, residents of 48 counties of western Virginia strongly opposed the action. They formed their own Unionist Virginia government, voted to declare themselves a new state, and applied for admission to the Union. West Virginia became a state in 1863.

Under Article 4, Section 3, Clause 2, Congress has full authority to make any rules and regulations regarding U.S. territories or possessions. It can delegate some power to make laws to a territorial legislature elected by residents of the territory but can also limit the scope of that body's powers.

An interstate compact is an agreement between two or more states, or the federal district, that enables them to solve shared problems. For example, the Washington, D.C., Metro train system travels in Virginia, Maryland, and the District of Columbia. All three entities participate in the management, maintenance, and funding of the system, which benefits citizens from all three locations. Such agreements, which must be approved by Congress, then becomes part of the laws of each of those entities. Under Article 1, Section 10, Clause 3, these agreements must be approved by Congress. Initially, states entered these compacts primarily to resolve boundary disputes as the borders of states were being established in the growing United States. Over time, Congress has approved a wide range of interstate compacts.

Common reasons for creating an interstate compact include agreement to alter state boundaries, formation of a study commission to examine problems that affect more than one state or to promote common causes, or the issuance of regulations that apply to multiple states. Today, some compacts are regional and even national, rather than just among two or three states.