Federalism in US history is the record of how the United States has divided governing power between a national government and the fifty states, and how that division has moved back and forth over more than two centuries. It began with a confederation so weak the country nearly came apart, was rebuilt in 1787 into a genuine two-level system, and has been reshaped since by civil war, constitutional amendments, Supreme Court rulings, and the leverage of federal money. The balance has never held still.
Why the First American Framework Failed
The country’s first governing document, the Articles of Confederation, kept nearly all real power with the individual states. The central government could not levy taxes and had to rely on voluntary contributions from state legislatures to fund operations and pay war debts.1National Archives. Articles of Confederation Congress could not regulate trade between states or with foreign nations, and it had no way to enforce its own resolutions.2Constitution Annotated. ArtVI.C2.2.1 Articles of Confederation and Supremacy of Federal Law There was no executive branch to carry out legislation and no national court system to settle disputes.
The consequences were concrete. States imposed competing tariffs on each other’s goods, setting off trade wars. The national government could not maintain an adequate military, a weakness laid bare during Shays’ Rebellion in 1786 and 1787, when debt-burdened farmers in western Massachusetts shut down courthouses to block foreclosures and a privately funded state militia had to end the uprising. That episode alarmed George Washington, Alexander Hamilton, and James Madison, who read it as evidence the Articles could not hold the country together.
In February 1787, Congress called a convention of state delegates in Philadelphia to revise the Articles. The delegates scrapped them and drafted a new Constitution built around a genuinely federal system: real authority for a central government, and the states preserved as independent political units.
How the Constitution Divided Power
The 1787 Constitution rests on a few interlocking provisions. Article I, Section 8 lists the specific powers granted to Congress: taxing, borrowing, regulating interstate and foreign commerce, coining money, declaring war, raising armies, and establishing post offices, among others.3Constitution Annotated. Article I Section 8 – Enumerated Powers Those are the federal government’s enumerated powers. Under the Tenth Amendment, everything else belongs to the states or to the people.4Congress.gov. Tenth Amendment
Some powers are shared. Both levels can tax, build roads, operate courts, and borrow money. These concurrent powers mean federal and state authority overlaps across much of daily life.
When overlap turns into direct conflict, Article VI’s Supremacy Clause resolves it. The Constitution and federal laws made under it are “the supreme Law of the Land,” and state judges are bound by them regardless of anything in state constitutions or statutes to the contrary.5Congress.gov. U.S. Constitution – Article VI That clause has been the backbone of federal authority in every contested area from banking to civil rights to environmental regulation.
The Marshall Court and the First Fights Over Federal Power
McCulloch v. Maryland (1819)
The scope of federal power reached the Supreme Court almost immediately. McCulloch v. Maryland asked two questions: could the federal government create a national bank when the Constitution never mentions banks, and could a state tax that bank out of existence?
Chief Justice John Marshall answered both. The Necessary and Proper Clause, he wrote, gives Congress authority to use any “appropriate and legitimate” means to carry out its enumerated powers, not only those that are “absolutely essential.”6Justia. McCulloch v. Maryland Chartering a bank was a reasonable way for Congress to manage the nation’s finances. Maryland’s tax was unconstitutional because, in Marshall’s phrasing, “the power to tax involves the power to destroy,” and a state cannot use its taxing authority to undermine legitimate federal operations.7National Archives. McCulloch v. Maryland
Gibbons v. Ogden (1824)
Five years later, the Marshall Court took up the Commerce Clause. New York had granted a monopoly on steamboat navigation in its waters, and the monopoly holder tried to block a competitor licensed under a federal coasting law. The Court ruled that the power to regulate commerce “extends to every species of commercial intercourse” among the states and “does not stop at the external boundary of a State.”8Justia. Gibbons v. Ogden The federal license won.
The decision opened interstate waterways and signaled that Congress, not the states, held the dominant hand over economic activity crossing state lines.9National Archives. Gibbons v. Ogden (1824) That principle would expand for the next two centuries.
The Nullification Crisis
Not everyone accepted federal supremacy. In 1832, South Carolina adopted an Ordinance of Nullification declaring the federal tariffs of 1828 and 1832 unconstitutional and unenforceable within the state. The nullification theory held that states, as sovereign parties to the constitutional compact, could void federal laws they deemed unconstitutional.
President Andrew Jackson rejected that view as incompatible with the survival of the union. In March 1833, Congress passed the Force Bill authorizing the president to use military force to collect the tariffs, alongside a Compromise Tariff that gradually lowered the disputed duties. South Carolina rescinded its Ordinance, though it symbolically nullified the Force Bill on its way out. The precedent was clear: states could not simply opt out of federal laws they disliked.
The Civil War Amendments and the Federal Guarantee of Rights
The Civil War settled the secession question by force. The Reconstruction amendments that followed reshaped federalism through law. The Thirteenth Amendment, ratified in 1865, abolished slavery throughout the United States and gave Congress power to enforce that prohibition through legislation.10National Archives. 13th Amendment to the U.S. Constitution: Abolition of Slavery (1865) For the first time, the Constitution directly overrode a practice states had long treated as a matter of local authority.
The Fourteenth Amendment, ratified in 1868, went further. It barred states from depriving any person of life, liberty, or property without due process of law and required every state to provide equal protection of the laws to all people within its borders.11National Archives. 14th Amendment to the U.S. Constitution: Civil Rights (1868) Before Reconstruction, the Bill of Rights restricted only the federal government. The Fourteenth Amendment changed that.
Over the following century and a half, the Supreme Court used the Fourteenth Amendment’s Due Process Clause to apply most of the Bill of Rights against the states through what became known as the incorporation doctrine. It worked case by case: the First Amendment’s speech and religion protections, the Fourth Amendment’s prohibition on unreasonable searches, the Sixth Amendment’s right to counsel, and eventually the Second Amendment’s right to bear arms. A few provisions remain unincorporated, including the Third Amendment’s quartering restriction and the Seventh Amendment’s civil jury right.
The Fifteenth Amendment, ratified in 1870, barred denial of voting rights based on race. Together, the three Reconstruction amendments made the federal government the guarantor of individual rights against state action.12United States Senate. Landmark Legislation: The Fourteenth Amendment
The Dual Federalism Era and How the New Deal Ended It
For roughly the first 150 years under the Constitution, the operating model was what scholars call dual federalism. Federal and state governments worked in largely separate spheres, each supreme within its own. The federal side handled defense, foreign affairs, and interstate commerce. States handled education, criminal law, family law, and most economic regulation. It’s sometimes called the “layer cake” model because the layers didn’t blend.
The Great Depression broke that arrangement. When the economy collapsed in the 1930s, state governments lacked the resources to address unemployment, bank failures, and collapsing farm prices. President Franklin Roosevelt’s New Deal asserted federal authority over economic life on an unprecedented scale, regulating wages, setting production quotas, creating federal jobs programs, and establishing Social Security.
The Supreme Court initially struck down several New Deal measures as beyond Congress’s commerce power. After Roosevelt’s landslide 1936 reelection and his threat to expand the Court, the justices began upholding broader exercises of federal authority. The pivotal case was Wickard v. Filburn (1942), which held that Congress could regulate a farmer growing wheat for his own household consumption. The reasoning was cumulative: if enough farmers did the same, the aggregate effect on the national wheat market would be substantial, so Congress could reach even purely local activity on that basis.13Justia. Wickard v. Filburn After Wickard, little economic activity remained beyond the Commerce Clause, and dual federalism was effectively dead.
Cooperative Federalism Through Federal Spending
What replaced dual federalism was deep entanglement. Rather than two separate layers, the modern system works more like a marble cake, with federal and state responsibilities blending together across nearly every policy area.
Money did most of the work. Federal grants-in-aid became the dominant mechanism for shaping state policy. The federal government offered states funding for highways, unemployment insurance, healthcare, education, and housing, and attached conditions: to get the money, states had to meet federal standards. States grew dependent on those dollars, which now represent a significant share of most state budgets.
The Supreme Court set guardrails in South Dakota v. Dole (1987), a case about a federal law that withheld 5% of highway funding from states allowing anyone under 21 to buy alcohol. The Court upheld the condition and laid out four requirements: the spending must promote the general welfare, the conditions must be clearly stated, the conditions must relate to a legitimate federal interest, and they cannot be independently unconstitutional or so coercive that states have no real choice.14Justia. South Dakota v. Dole
That last requirement decided National Federation of Independent Business v. Sebelius (2012), the landmark case on the Affordable Care Act. The ACA required states to expand Medicaid eligibility or lose all existing Medicaid funding. The Court struck down the condition as unconstitutionally coercive, calling it “a gun to the head.” Because Medicaid spending accounted for over 20% of the average state’s budget, threatening to revoke it entirely left states with “no real option but to acquiesce.”15Justia. National Federation of Independent Business v. Sebelius Congress can use money to encourage states, but it cannot threaten the loss of massive existing funding to force them into new programs.
New Federalism and a Limit on the Commerce Clause
Starting in the 1980s, a counter-movement pushed power back toward the states. President Ronald Reagan championed what became known as “New Federalism,” proposing to consolidate narrowly targeted federal grant programs into broader block grants that gave states more discretion. His broader agenda included shrinking the federal workforce and separating federal and state responsibilities in a way that resembled the older dual federalism model. Political resistance from governors and Congress limited the actual results to a modest consolidation of some social programs into block grants.
The Supreme Court gave the movement its most important legal victory in United States v. Lopez (1995). The Court struck down the Gun-Free School Zones Act, ruling that carrying a gun near a school was not economic activity with any meaningful connection to interstate commerce. The government argued that gun violence in schools harmed education and, through it, the national economy, but the Court rejected the chain as too speculative. Accepting it, Chief Justice Rehnquist wrote, would let Congress regulate “virtually any sphere of activity” and erase any real limit on the commerce power.16Justia. United States v. Lopez After more than fifty years of expanding Commerce Clause authority, Lopez marked the first time the Court drew a boundary.
The Anti-Commandeering Doctrine
Another major limit on federal power came through a line of cases establishing the anti-commandeering doctrine: the federal government cannot force state officials to carry out federal programs.
The principle first appeared in New York v. United States (1992). Congress had tried to require states to either regulate radioactive waste to federal specifications or take ownership of the waste themselves. The Court struck down the “take title” provision, holding that “Congress may not commandeer the States’ legislative processes by directly compelling them to enact and enforce a federal regulatory program.”17Justia. New York v. United States Congress can regulate individuals directly, but it cannot conscript state governments as enforcement agents.
The doctrine reached state executive officials in Printz v. United States (1997), which struck down provisions of the Brady Handgun Violence Prevention Act requiring local sheriffs to conduct background checks on gun buyers. Ordering local law enforcement to carry out federal tasks, the Court said, was “fundamentally incompatible with our constitutional system of dual sovereignty.”
Most recently, Murphy v. NCAA (2018) applied the doctrine to federal laws that prohibit states from acting. The Professional and Amateur Sports Protection Act had barred states from authorizing sports gambling. The Court struck it down, reasoning that the distinction between compelling a state to pass a law and prohibiting a state from passing one is meaningless. Either way, “state legislatures are put under the direct control of Congress.”18Supreme Court of the United States. Murphy v. National Collegiate Athletic Association States gained the freedom to legalize sports betting, and many quickly did.
Anti-commandeering does not stop the federal government from achieving its policy goals. Congress can still regulate individuals directly, offer states financial incentives to cooperate, or use federal agencies to enforce federal rules. What it cannot do is treat state governments as subordinate agencies required to implement federal policy.
How Preemption Resolves Federal-State Conflicts
When federal and state laws collide, the Supremacy Clause says federal law wins. Determining whether a real conflict exists is more involved than it sounds, and the doctrine of preemption governs those determinations.
Preemption takes two basic forms. Express preemption is when a federal statute explicitly says it overrides state law in a particular area. Implied preemption is when Congress hasn’t said so directly, but the structure and purpose of the federal scheme suggest displacement was intended. Implied preemption splits further. Field preemption applies when federal regulation is so pervasive that no room remains for state rules in the same area. Conflict preemption applies when it is physically impossible to comply with both federal and state law, or when state law creates an obstacle to federal objectives.19Congress.gov. Federal Preemption: A Legal Primer
The Supreme Court has generally applied a presumption against preemption in areas of traditional state authority like health, safety, and land use. Federal law should not be read as displacing state police powers “unless that was the clear and manifest purpose of Congress.” The presumption gives states breathing room, but it yields when Congress speaks clearly or the federal regulatory scheme genuinely occupies the field.
Where Federalism Is Being Tested Today
Federalism is not a historical relic. It generates active, high-stakes conflicts on a regular basis.
The most visible ongoing example involves marijuana. Under the federal Controlled Substances Act, marijuana remains a Schedule I substance, strictly prohibited under federal law. Most states have legalized marijuana for medical use, recreational use, or both. Federal law recognizes no distinction between medical and recreational marijuana. Reclassifying marijuana to a lower federal schedule, without other legal changes, would still not bring state-legal marijuana businesses into compliance with federal law.20Congress.gov. The Federal Status of Marijuana and the Policy Gap with States
Congress has managed the tension through appropriations riders rather than legislation. Since fiscal year 2015, annual spending bills have prohibited the Department of Justice from using federal funds to prevent states from implementing their own medical marijuana laws. Federal courts have read that rider to block certain federal prosecutions of individuals complying with state medical marijuana programs, though it provides no protection for recreational marijuana operations. Federal banking regulators have not issued formal guidance for financial institutions serving marijuana businesses, leaving those businesses largely shut out of the banking system.
Similar disputes run through immigration enforcement, environmental regulation, and gun policy, where states have sometimes pushed beyond federal law and other times refused to help enforce it. Anti-commandeering means the federal government cannot force state and local police to enforce federal immigration law, but it can use its own agents and tie federal funding to cooperation.
These conflicts reflect the same structural tension the framers built into the system in 1787: a federal government strong enough to act on national problems, and state governments independent enough to resist when they believe federal policy is wrong. The balance keeps evolving through legislation, litigation, and the practical realities of governing a country where policy preferences vary sharply from state to state. Federalism was never designed to produce a permanent settlement. It was designed to channel disagreement into a framework that could absorb it without breaking.