The supremacy clause establishes federal law as the highest authority

John Marshall advanced federal supremacy and judicial review

Marshall's jurisprudence emphasized that the Constitution is the supreme law of the land, enforceable by an independent judiciary. Through his court's decisions, he affirmed judicial review, broad implied powers for Congress, and federal authority to override conflicting state laws.

When state and local laws conflict, state law almost always prevails

Courts generally side with state law when it conflicts with a local ordinance. Whether the contradiction is explicitly stated or merely implied by the two laws, state authority typically prevails.

Parliament is the supreme legal authority under the UK's constitutional system

The principle of "parliamentary sovereignty" holds that the UK Parliament can make or repeal any law, and that courts cannot invalidate its legislation. Judicial bodies can reshape governance, but parliamentary laws remain legally supreme.

The commerce clause gives the federal government authority to regulate interstate economic activity

This short constitutional provision has allowed Congress to regulate everything from wheat production to racial segregation, greatly expanding federal power by linking national authority to interstate economic activity.

The 10th Amendment affirms that most undelegated powers remain with the states

Adopted to reassure skeptics of an overly powerful federal government, the amendment was meant to curb federal overreach and preserve state control over most everyday governance decisions.

States are increasingly using preemption laws to override local decisions

Preemption laws enable state legislatures to prevent cities and counties from enacting their own rules on issues like minimum wage, gun control, and housing. Their use has increased significantly in recent years.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

In the US, any court can rule on constitutionality—unlike in most other countries

In the American system, known as diffuse judicial review, federal and state courts at every level may assess whether laws comply with the Constitution, and their decisions are ultimately reviewable by the Supreme Court. Many other democracies, by contrast, reserve constitutional review to specialized constitutional courts.

The United States is the world's oldest continuously operating federal system under a written constitution

The US pioneered federalism in the late 18th century, and many countries later adopted federal systems to manage conflict and share power. This resource features interactive maps that trace the spread of federal systems worldwide from 1900 to the present.

The Supreme Court has never definitively settled federal war powers

Despite more than two centuries of conflict over war powers, the Supreme Court has consistently avoided defining the precise boundary between congressional and executive authority, leaving that boundary to be contested by the political branches.

The Constitution grants Congress more powers than the president

Article I outlines detailed congressional powers—taxation, spending, war declarations, and lawmaking—while Article II gives the president limited, broadly defined authority. This design reflects the framers' intention to prevent executive overreach.

Federalism creates tension between national and state power by design

Federalism assigns authority so that neither the national government nor the states entirely dominate the other or the people they govern. By creating overlapping claims of power, the system makes negotiation, conflict, and compromise a permanent feature rather than a failure.

The Civil War permanently strengthened federal power

The Civil War expanded federal power through emancipation, national military mobilization, and postwar civil rights laws, permanently strengthening the national government and shifting the balance of authority away from the states.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

The man who gave 9 people power over everyone

In the US, nine unelected justices can shape some of the most personal and political parts of our lives. But the Supreme Court wasn't always this powerful. When it was first written into the Constitution, it had no clear authority, no real role, and little public respect.

Read the language in the Constitution that protects religious freedom in the US

The First Amendment's religion clauses include two provisions: the establishment clause and the free exercise clause. These two parts prevent the government from endorsing any specific religion and from interfering with the free practice of religion.

Every US state constitution references God or the divine, though the federal Constitution does not

God or the divine is mentioned at least once in all 50 state constitutions and nearly 200 times overall. Massachusetts has the most, with eight references, and four states do not use the word "God" but instead refer to a "Supreme Being" or "Divine Guidance."

The US has 575 federally recognized tribal nations, each a sovereign government

Tribal governments are sovereign, with authority to pass laws, run courts, and levy taxes on their lands. Unlike cities or counties, they are not created by states. Their sovereignty predates the United States itself and is recognized in the Constitution, treaties, and federal law.

The Federal Reserve is the most powerful financial institution in the US

The Fed controls the money supply, determines interest rates, and regulates the banking system. Established in 1913 after a volatile series of financial panics, the central bank has managed to retain its legitimacy despite broad critiques against its obscure and independent decision process.

The president can federalize state National Guard units during national emergencies

While the governor usually commands their state's National Guard, the president can assume control—federalizing the guard—under laws like the Insurrection Act or Title 10. Once federalized, troops operate under the US military chain of command.

The rivalry between Alexander Hamilton and Thomas Jefferson centered on federalism—the question of how much power the federal government should hold relative to the states.

The 14th Amendment established birthright citizenship and equal protection under law

Ratified in 1868, the 14th Amendment guaranteed citizenship to all people born in the United States and required states to provide equal protection—overturning the Dred Scott decision, which had declared that Black Americans could never be citizens or claim constitutional rights.

The Clean Water Act became the national standard for protecting American waters

Enacted in 1972, the Clean Water Act grants the Environmental Protection Agency the authority to regulate pollutant discharges, establish water quality standards, and oversee water pollution controls. Its scope has narrowed due to recent Supreme Court rulings.

An adultery and poisoning case examined whether federal treaty power supersedes state law

This Radiolab podcast unpacks Bond v. United States, where a local love-triangle assault became a federal case under an international treaty—forcing the Supreme Court to confront a founding question: How far can federal power reach into crimes traditionally handled by the states?

The Senate's filibuster—a procedure that allows for unlimited debate—is not in the Constitution

In the United States Senate, the filibuster enables senators to delay or block legislation. Ending debate became possible in 1917 with a cloture rule requiring a two-thirds vote. In 1975, that was changed to 60 votes in most cases.

The presidential line of succession ensures continuity of government

If the president dies, resigns, or is removed from office, the vice president assumes the presidency. The line then proceeds to the speaker of the House, Senate president pro tempore, and Cabinet secretaries, beginning with the Department of State, established under the Presidential Succession Act.

Long after his death, Washington was made the highest-ranking military figure in US history

Only three Americans have held the rank of General of the Armies: John J. Pershing, Ulysses S. Grant, and Washington. However, Washington still outranks the others because Congress passed a 1976 law stating that he outranks all officers "past or present."

The Department of Justice is led by the US attorney general

The attorney general acts as the nation's top law enforcement official—managing all Department of Justice activities, overseeing US attorneys, and advising the president and federal agencies on legal issues that influence policy and enforcement.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

Despite being favored by 87% of Americans, Congress does not have term limits.

See this overview of the firework rules across all 50 states, ranging from a complete ban on non-professional fireworks in Massachusetts to states with more lax rules like Indiana.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

See a ranking of the best (and worst) Federal Reserve Chairs since 1914 out of the 16 men and women who have held the office since.

The story of Dollree Mapp, whose legal challenge over her 1957 conviction for possessing "obscene material" led to a major strengthening of the Fourth Amendment

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

View the ten deadliest tornadoes in US history.

Explore fun facts from the USPS, including unique post office buildings, a stamp that traveled past Pluto, and more.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

A small portion of The Winstons' 'Amen, Brother,' an obscure '60s gospel record, is the basis for thousands of hip-hop tracks, making it one of the most sampled records ever that's informally known as 'the Amen break.'

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

'Shogun,' a 1980s TV series, helped popularize sushi in the US by stimulating an American interest in Japanese culture.