Article 10 of the Constitution, as most people mean the phrase, is really the Tenth Amendment. The original Constitution has only seven articles, so a search for “Article 10” almost always points to the tenth entry in the Bill of Rights, ratified in 1791.1Congress.gov. Historical Background on Tenth Amendment In one sentence, it says that any power the Constitution does not give to the federal government, and does not forbid to the states, belongs to the states or to the people. It is the structural rule that keeps Washington’s authority limited and state governments independent.
The Exact Text
The amendment reads: “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.”2Congress.gov. Tenth Amendment
That single sentence carries the weight of a long argument. During ratification, opponents of the new Constitution feared a strong central government would swallow the states the way the British Crown had governed the colonies. The Tenth Amendment was written to answer that fear directly, as part of the Bill of Rights.3National Archives. Bill of Rights (1791)
One word missing from the text matters as much as the words that appear. The framers left out “expressly” before “delegated.” The earlier Articles of Confederation had limited the national government to powers “expressly delegated,” and that language proved too rigid to run a country. Dropping it allowed federal power to reach beyond the literal text through provisions like the Necessary and Proper Clause, while still preserving the amendment’s core principle.4GovInfo. Tenth Amendment – Reserved Powers Chief Justice John Marshall put it early on: whether a particular power belongs to the federal government or to the states depends on “a fair construction of the whole instrument,” not a rigid word search.
What “Reserved to the States” Means in Practice
The Tenth Amendment starts from a simple historical fact. The states existed as independent governments before the Constitution was ratified. They did not receive their authority from the federal government; they kept everything they did not hand over. So in any area where the Constitution is silent, the default is state jurisdiction.
That default covers enormous ground. State legislatures set criminal penalties, regulate public health, run education systems, oversee elections, administer family law, and license professions. Lawyers call this cluster the “police powers,” meaning the broad authority to protect the health, safety, and welfare of residents. No federal statute grants these powers to the states. They simply never gave them up.
Justice Louis Brandeis described the practical value of the arrangement in 1932, writing that “a single courageous State may, if its citizens choose, serve as a laboratory; and try novel social and economic experiments without risk to the rest of the country.” Healthcare reforms, minimum-wage changes, marijuana laws, and emissions rules have all followed that pattern.
What “To the People” Adds
The final four words matter on their own. Power that is not delegated to the federal government and not held by the states is reserved to the people. This is the principle of popular sovereignty: all government authority ultimately flows from individuals, and silence in the Constitution does not translate into an unlimited grant of power to anyone.
The Tenth Amendment works in tandem with the Ninth, which says that listing specific rights in the Constitution does not mean those are the only rights people have. Justice Potter Stewart described both amendments as sharing the same core idea: “all is retained which has not been surrendered.”5Congress.gov. Ninth Amendment Doctrine The Ninth blocks the government from claiming an unlisted right does not exist. The Tenth blocks it from claiming an unlisted power was granted by default.
Courts rarely use either amendment as a standalone basis to strike down a law. When someone challenges federal action as exceeding constitutional authority, the judicial question focuses on whether Congress was acting under a legitimately granted power in the first place. If it was, a Tenth Amendment claim fails. The real force of the “to the people” language is that it places the burden of justification on the government whenever authority is in dispute.
How Courts Enforce It: The Anti-Commandeering Doctrine
The strongest protection the Tenth Amendment gives states is the anti-commandeering doctrine. Congress cannot force state governments to carry out federal programs. Three Supreme Court decisions built the rule.
In New York v. United States (1992), the Court struck down a federal law that effectively ordered state legislatures to pass regulations for radioactive waste disposal. Congress, the Court held, “may not simply commandeer the legislative processes of the States by directly compelling them to enact and enforce a federal regulatory program.”6Legal Information Institute. Anti-Commandeering Doctrine Congress can encourage, incentivize, and fund. It cannot order.
Five years later, Printz v. United States (1997) extended that protection to state executive officials. The federal Brady Act had required local law enforcement to conduct background checks on handgun buyers. The Court held that the federal government cannot press state officers into service to administer federal programs.7Justia. Printz v United States State governments are independent political actors, not federal field offices.
The most recent major ruling came in Murphy v. National Collegiate Athletic Association (2018), which struck down a federal law prohibiting states from authorizing sports betting. Telling a state it cannot legalize something, the Court said, is just as much commandeering as telling it that it must regulate something.8Justia. Murphy v National Collegiate Athletic Association Within a few years, dozens of states legalized and regulated sports betting on their own terms.
When Federal Law Still Wins
The Tenth Amendment does not make states untouchable. Article VI, the Supremacy Clause, declares the Constitution, federal statutes made under it, and treaties to be “the supreme Law of the Land,” binding state judges regardless of contrary state law.9Congress.gov. Article VI Clause 2 – Supreme Law When a valid federal law conflicts with a state law, the federal law prevails. This is preemption, and it comes in a few forms.
Express preemption is written into the statute. Congress states plainly that federal law overrides state law on a subject. The Employee Retirement Income Security Act does this for most state laws relating to employee benefit plans. Implied preemption is messier. It arises when Congress has regulated a field so thoroughly that no room is left for state regulation, or when compliance with both federal and state law is impossible.10Congress.gov. Federal Preemption – A Legal Primer
In areas states have traditionally governed, such as health, safety, and land use, courts apply a “presumption against preemption.” When a federal statute is ambiguous about displacing state law, courts lean toward letting the state law survive. The presumption is not absolute, but it gives states a meaningful advantage in litigation over regulatory overlap.
The federal side of the ledger is also constrained by the enumerated-powers principle. Article I, Section 8 lists what Congress can do: tax, spend, regulate interstate commerce, declare war, raise armed forces, run post offices, and a handful of others.11Congress.gov. Article I Section 8 – Enumerated Powers If a power is not on the list and cannot fairly be tied to one that is, the federal government has no authority to act. In United States v. Lopez (1995), the Court struck down a federal law banning guns near schools, holding that gun possession in a school zone was not economic activity and did not substantially affect interstate commerce.12Constitution Annotated. United States v Lopez and Interstate Commerce Clause
Federal Money, Strings, and Coercion
Congress cannot order states to run federal programs, but it can offer them money on condition. Speed limits, drinking-age minimums, and education standards have all been enforced this way. The Supreme Court set the ground rules in South Dakota v. Dole (1987): spending conditions must be unambiguous, related to the federal interest in the program, and in pursuit of the general welfare, and cannot require states to do anything independently unconstitutional.13Justia. South Dakota v Dole
The critical limit is coercion. Offering new money is fine. Threatening to strip away funding a state already depends on is not. The Court drew that line for the first time in National Federation of Independent Business v. Sebelius (2012). The Affordable Care Act required states to expand Medicaid eligibility dramatically or lose all existing Medicaid funding, which for an average state amounted to more than a fifth of total state spending. The Court held that threatening the withdrawal of that much existing money crossed from encouragement into coercion, and made the expansion optional instead.14Justia. National Federation of Independent Business v Sebelius
What States Still Run Day-to-Day
Even after decades of expanding federal reach, states retain primary control over the areas that touch most people’s lives most directly.
Criminal Law
States write their own criminal codes, set their own penalties, and run their own courts and prisons. The federal criminal code covers a relatively narrow set of offenses tied to interstate activity, federal property, or federally regulated industries. For the overwhelming majority of crimes, state prosecutors and state judges handle everything.
Education
State boards of education set curriculum standards, graduation requirements, and teacher certification rules. Federal funding programs come with compliance strings, but the actual operation of public schools remains a state and local responsibility.
Elections
States administer elections, including federal ones. Under the Elections Clause, state legislatures establish the rules for congressional elections, from voter registration to ballot design to vote counting.15Constitution Annotated. States and Elections Clause Congress can override state rules by passing uniform federal requirements, but absent that, the states run elections. Voter qualifications are governed separately by other constitutional provisions, including the Fourteenth, Fifteenth, Nineteenth, and Twenty-Sixth Amendments.
Family Law
Marriage, divorce, child custody, adoption, and probate are all governed by state law. Federal courts have historically declined jurisdiction over domestic-relations cases. Constitutional rulings can set minimum standards, but the day-to-day regulation of family relationships stays with the states.
Professional Licensing
Lawyers, doctors, engineers, teachers, and dozens of other professionals need a license from the state where they practice. Each state sets its own educational requirements, exams, and disciplinary processes, which is why a license earned in one state does not automatically transfer to another. To reduce that friction, states have joined voluntary interstate compacts. The Interstate Medical Licensure Compact now includes over 40 member jurisdictions and has issued nearly 200,000 licenses since its creation. Those compacts are agreements among states, not federal mandates.
Intrastate Business
Business transactions that occur entirely within one state fall under state regulation. This covers registration, licensing, utility rates, and local transportation. Federal regulation applies only when activity crosses state lines or touches a federally regulated industry. One outer limit runs the other way: under the dormant Commerce Clause, a state cannot pass laws that discriminate against out-of-state businesses or wall off its market from interstate commerce.