Federal systems are a minority among the United Nations' 193 members

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.

Explore the countries with a federal system—and see how they work

This resource from the Forum of Federations catalogs the world's federal countries. It provides background information on each, including the emergence of federalism, the division of power, and the practical interaction between national and regional governments.

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 debate over federalism helped produce the novel character of the United States

During ratification, Federalists argued that a strong national government was essential for national survival. Anti-Federalists warned that it could overwhelm states and threaten individual liberty—forcing compromises that shaped early American federalism and led to the adoption of the Bill of Rights.

Courts referee federalism disputes between Congress and the states

Modern federalism is primarily worked out through litigation. The Supreme Court decides disputes in written opinions that explain when federal law preempts state authority, how far Congress's powers extend, and when states may resist.

Immigration enforcement shows how federalism plays out on the ground

In recent years, federalism has shifted from allowing policy diversity across states to open conflict, with states and the federal government increasingly trying to impose their preferences on one another over issues like abortion, voting, immigration, and public health.

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 Articles of Confederation were not a federal system

Ratified in 1781, the Articles of Confederation left the states sovereign and independent, denied the national government power to tax or regulate commerce, and forced Congress to act through the states—exposing the limits of confederation and paving the way for US federalism.

Colonial self-rule fostered strong autonomy and distrust of centralized power

American colonies were governed through a patchwork of different systems, ranging from Crown-run to locally controlled. Broad local autonomy—often followed by sudden imperial crackdowns—taught colonial leaders to prize home rule and distrust distant centralized power, attitudes that later informed US federalism.

The Federal Reserve is the central bank of the US

No institution wields more power in US finance than the Federal Reserve—but opinion polls indicate that most Americans don't know what it does. Curious about the country's central bank? 1440's got your breakdown of how the Federal Reserve works.

Hamilton proposed one of the strongest visions of national government

At the Constitutional Convention, Alexander Hamilton advanced a plan modeled partly on Britain's system, calling for a powerful national executive and for senators to serve for life (with good behavior)—proposals that failed to gain widespread support.

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 supremacy clause establishes federal law as the highest authority

The supremacy clause states that the United States Constitution and federal laws enacted under it supersede conflicting state laws, ensuring national authority prevails when federal and state governments disagree.

There are 6 primary governing bodies at the UN

The United Nations is structured around six main bodies: the General Assembly, Security Council, Economic and Social Council, Trusteeship Council, International Court of Justice, and Secretariat. Each plays a distinct role in promoting peace, justice, and cooperation worldwide.

The reservation system gives tribes limited self-governance while keeping them under federal control

Federal law designates Native nations as "domestic dependent nations"—a legal category that recognizes limited tribal sovereignty while subordinating tribes to federal authority. This ambiguous status, introduced by Chief Justice John Marshall's 1831 opinion in Cherokee Nation v. Georgia, has shaped conflicts over land and governance ever since.

Map of union membership by state

In the United States, unions exist across the entire country, but some states have more union members than others. Multiple reasons exist: from policy differences across states, to industrial and cultural influences. Want to learn more? Find out which state has the highest percentage of union membership, and which one has the lowest, through this map.

American local government comes in five distinct forms

Counties, municipalities, townships, special districts, and school districts are each created for a different purpose, operating under different rules, and answerable to the state in different ways. Special districts, the least known of the group, are created for specific purposes, such as transit or fire protection.

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

How presidential systems differ from parliamentary governments

In presidential systems like the US, the executive and legislature are separately elected, giving presidents fixed terms and independent authority. In parliamentary systems, executives are elected by legislatures and can be removed by a simple vote of no confidence.

The New Deal shifted economic and social authority to the federal government

Franklin D. Roosevelt's response to the Great Depression expanded federal power through economic regulation and social welfare programs, permanently reshaping federalism by shifting responsibility for financial security to Washington while leaving states to administer many of these programs.

Federal spending falls into 2 categories: mandatory and discretionary

Federal spending is split between mandatory programs, funded automatically by law, and discretionary programs, funded through annual appropriations. This video breaks down which major programs fall into each category and why the distinction matters.

The US federal government employs roughly 3 million people

Tracking began in 1939, when the federal workforce consisted of about 1 million people. The total peaked in 1990 at 3.4 million, and hit a recent low in 2014 at 2.7 million.

The South was placed under federal military rule during Reconstruction

Beginning in 1867, the Reconstruction Acts divided 10 former Confederate states into five military districts, each governed by a Union general. Federal troops supervised elections, enforced civil rights, and maintained order under direct congressional authority.

Many religions have core majorities in certain countries

Though most religions have members across the world, they also have major concentrated populations in specific nations. For example, 95% of Hindus live in India, while 85% of the world's Jews live in Israel and the US.

The firms running America's voting systems

Three companies make up over 90% of the US market share around voting systems, and like any company, they're priorities aren't always aligned with the public's. Dive into the industry of voting machines in this investigation piece from the Guardian.

The world is shifting from unipolarity toward a multipolar order

The post-Cold War world was briefly unipolar after 1991, with the US standing alone as a global superpower following decades of US-Soviet bipolarity. Analysts increasingly describe today's order as multipolar, with China, Russia, the US, and regional powers all competing for influence.

How China's 'one country, two systems' works

"One country, two systems" is a principle put forth by the People's Republic of China as its approach toward formerly independent regions like Hong Kong and Macau. Supposedly promising administrative independence, China has not always been consistent in its application. Currently, it plans to offer the same arrangement with Taiwan. Learn more in this brief video.

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

Calculate how much of your tax dollars go to each federal program based on your income, filing status, and number of children

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

The idea for the Federal Reserve was conceived in secret in 1910—with bankers donning duck hunt gear for disguise while traveling to a remote country club on Georgia's Jekyll Island

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.

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

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

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.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

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.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

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

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

The Brothers Grimm were lawyers before they were storytellers, but became interested in fairy tales as they began investigating how rules and customs had been passed down through cultures.

Learn how monoclonal antibodies, which mimic the body's antibodies, can fight diseases like Ebola.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.