The US officially adopted an income tax in 1913

Over a century ago, fewer than 1% of Americans paid income taxes—but the cost of World War II prompted the federal government to greatly expand the number of people required to pay income taxes.

On July 1, 1862, the agency now known as the Internal Revenue Service was established and named the Bureau of Internal Revenue

It was created to collect the first-ever US income tax, which was created to help pay for the Civil War. After gaining their independence from Britain, Americans were skeptical about giving the federal government absolute power to collect federal income taxes. As a result, early US tax laws dictated that direct taxes, like income taxes, had to be directly apportioned to a state's population. The nation went back and forth on its federal tax laws multiple times. For instance, in 1872, the income tax from the Civil War was repealed. But it was revived in 1894, and then repealed again in 1895. In 1913, Congress passed the 16th Amendment, giving Congress the power to levy income taxes on individuals and corporations without apportioning the burden among the states in line with population, once and for all.

The 16th Amendment paved the way for capital gains taxes

Ratified in 1913, the 16th Amendment paved the way for a far-reaching federal income tax and supercharged the country’s coffers. Before then, the US depended on import tariffs and so-called consumption taxes to raise revenue.

Capital gains taxes were first levied in the US in 1913

However, up until 1921, they were treated the same as ordinary income. Ever since then, rates have swung up and down.

The IRS—a division of the US Treasury Department that enforces the Internal Revenue Code, collects taxes, and enforces tax laws—has been a frequent victim of arson over the years.

Since 1913, Americans have paid income taxes at varying rates

In the 2020s, the top marginal tax rate has floated around 37%, relatively lower than previous eras. Some have called for boosting the rate significantly to tax the highest earners.

Before the 16th Amendment, US tax law required direct taxes to be directly apportioned to a state's population

Due to these requirements, the federal government could not impose many direct taxes. Direct taxes include property and income taxes, whereas indirect taxes include duties and excises.

Individual income taxes are the federal government's primary revenue source, see a tracker that breaks down where the rest of the budget comes from

The US government historically makes nearly half of its total revenue last year from individual income taxes. But the US makes also makes money from a variety of other sources, including Medicare taxes and corporate income taxes. However, the federal government has run a deficit since 2001—reaching a peak of $3.13T in 2020.

Read why some states are considering imposing a flat tax rate that isn't adjusted by income

Wisconsin was the first US state to impose a state income tax, close in time to when the federal income tax went into effect. Many states followed suit, but nine states to this day still don't levy wage-related taxes.

Death taxes have helped fund wars since the 1860s

Death taxes date back to 700 BCE and were used in Ancient Rome and Ancient Egypt. In the US, they've been used to finance wars since the Civil War, and have been levied on both the estate and beneficiary. The estate tax created during WWI to help finance war efforts is still in effect today.

See a timeline of the IRS's history, including the introduction of standard deductions and the digitization of the filing process

The Commissioner of Internal Revenue was created in 1862 to take over federal tax collection after the President enacted a temporary income tax. That agency eventually became today's Internal Revenue Service.

Tariffs once fueled the US economy, historically serving as a primary source of revenue and a means to protect domestic industries.

How the federal income tax affected Prohibition

In the early 1900s, 30% to 40% of government tax revenue came from liquor, wine, and beer, a reliance that made Prohibition seem like a fiscal impossibility. But the passage of the federal income tax in 1913 changed the calculus, which helped allow the government to ban alcohol production and sales.

Learn how the US tax code works and why it's important

First published in 1926, the US Code is the official codification of federal statutes in the US. Title 26 of the US Code, for instance, lists all of the federal tax laws of the United States. A new edition is published every six years.

Americans between the ages of 45 and 55 pay nearly 30% of all income taxes, paying an average tax rate of around 17%.

Understanding the low corporate tax rate in the US

Corporate taxes, which make up roughly a third of the federal government's revenue, have been calculated using a flat 21% rate since the Tax Cuts & Jobs Act of 2017. The current rate is considered low both by historic standards (it averaged over 50% in the 1950s and 1960s) and compared to other countries.

Revenue from tariffs goes to the US Treasury's general fund.

See how income taxes in the US compare to those of other countries.

Opponents of the federal estate tax began using the term 'death tax' in the 1940s to sway public opinion.

Watch this video to learn how US tax brackets actually work.

Why the rich don't pay taxes like you do

The system behind the US income tax isn't as straightforward as it looks. You earn money. Taxes get taken out. Case closed … right? Not exactly. In this episode of "1440 Explores," we break down how the US tax system actually works, from confusing deductions and misunderstood tax brackets to why the wealthiest Americans often end up paying a very different tax than everyone else.

What America's 1% pays in taxes, by state

In the US, the top 1% of earners contribute 45% of all personal income taxes collected nationwide. But not all states are created equal when it comes to income tax. Some states are more dependent on the 1% than others for tax revenue. SmartAsset recently examined IRS tax return data to determine exactly how much the top 1% of earners in each state paid in taxes. Find your state here.

The US has carried debt since 1791

After the Revolutionary War, the US owed $75M to nations like France. Debt builds when spending exceeds revenue, funding programs, wars, and economic recovery efforts. Most debt is domestic, like Social Security bonds, with foreign nations also holding a share.

The Tariff Act of 1789 was one of America's first acts.

See how the federal estate tax has changed in the 21st century

In 2001, the government passed an act to completely repeal the tax. It was overturned in 2010. In 2017, the government increased the exemption threshold so fewer people would have to pay into the tax. In 2025, the exemption threshold was permanently set to $15M.

The most taxed states in America

Some states in the US have higher taxes than others. Hawaii, for instance, has the highest total tax burden in the country at 13.9%, whereas Alaska has the lowest overall tax burden at 4.9%. New York has the highest individual income tax burden; and eight states have no individual income tax. See a map of the most-taxed US states here.

In addition to collecting taxes, issuing tax refunds, and performing audits, the IRS is tasked with enforcing the laws listed in the Internal Revenue Code

The Internal Revenue Code is also known as Title 26 of the US Code. It was enacted in 1925 and outlines income, estate, sales, payroll, and excise tax laws.

80% of Americans are bothered that some wealthy people don't pay their fair share of taxes

That's according to data from Pew Research Center. While most people are primarily taxed on their wages, many people in America's 1% derive much of their income from investments instead, which are often taxed at preferential capital gains rates. This structure was shaped by a series of legislative cuts that began in earnest with the 1978 Revenue Act and the 1981 Economic Recovery Tax Act.

The Budget and Accounting Act of 1921 created the modern federal budget

Before 1921, federal funding was fragmented and ad hoc. This article traces how inefficiency and postwar pressures led Congress to pass the Budget and Accounting Act, creating a standardized, centralized federal budgeting process.

The federal government's decision to pay off the states' Revolutionary War debts required a new tax, which sparked an armed rebellion. 

Death taxes are placed on a deceased person's estate

Death taxes can include liquid cash, property, stocks, or other financial assets they owned. There are two main types of death taxes in the US: the estate tax and inheritance tax. Death taxes are levied at the federal and state level, but are targeted towards the rich.

The highest inflation ever recorded in US history was estimated at 30% in 1778, just after the Revolutionary War.

Alexander Hamilton consolidated the states' debts, implemented a tax system, and established a national bank.

Why do long-term capital gains get taxed at preferential rates?

The 1920s defined capital gains as “unearned” taxable income—as opposed to “earned” income from jobs—and set into practice preferential tax rates for long-term capital gains that are hotly debated to this day. This historical review explores how voices in favor of preferential rates were arguing on behalf of greater market liquidity and incentive for investment activity. Learn more about the real history of capital gains tax rates here.

In 1792, Congress established the first national mint to produce all the coins in the US

At the same time, the US also started producing the dollar, its first official currency. The US Mint has since issued coins throughout the country.

The US has used a wide variety of different currencies between the 1690s and today

From colonial money to national banknotes, people have used all kinds of forms of currency throughout the history of the United States before settling on the dollar bills and quarters that we pay for things with today.

Historically, only about 1% to 2% of Americans had to pay the federal estate tax

Recent IRS data shows that between 2011-16, that number dropped even lower: The federal estate tax only impacts about 0.2% of Americans. Death taxes typically only impact the rich, and the federal estate tax is no exception.

Charting where federal revenue comes from

About 50 percent of federal revenue comes from individual income taxes, 7 percent from corporate income taxes, and another 36 percent from payroll taxes that fund social insurance programs. See breakdown in charts here.

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.

Tax policy can have a direct impact on the national debt, with past presidents' changes to tax codes inflating the deficit.

The history of bankruptcy in the US dates back to the signing of the Constitution

In 1787, this founding document gave Congress the right to establish nationwide bankruptcy laws. Legislators took advantage of that power in 1800 when they passed the Bankruptcy Act of 1800, the first comprehensive bankruptcy law at the federal level.

Roth IRAs were first introduced in the Taxpayer Relief Act of 1997

The Roth IRA is one of the most popular retirement accounts in the US. Nearly a quarter of Americans contributed to a Roth IRA in 2023. But this type of financial account hasn’t been around for that long.

How tax laws helped the federal government catch mob bosses during Prohibition

The IRS arrested top mob bosses during Prohibition after the Supreme Court ruled illegally-made income could be taxed. The IRS's biggest catch was Al Capone, who was charged with tax evasion and sentenced to 11 years in prison. But Capone wasn't the only bootlegger the IRS nabbed for tax evasion during this era.

It cost the IRS $0.36 to collect $100 in 2024

It costs the IRS a significant amount of money to do part of its job—collecting money. For instance, the Internal Revenue Service spent $16.1B to collect $4.7T in taxes in 2023.

The .1% of Americans once controlled 7% of all US wealth. Today, they control closer to 18%.

The US framework of government has influenced the constitutions of many other countries

In 1787, the US Constitution introduced a system built on the separation of powers and individual liberties, including freedom of speech and religion. Though widely influential, its rigidity has made it less of a modern model as countries adopt more adaptable constitutional frameworks.

See a chart showing how US tariff revenue has grown in recent years.

Most Americans take the standard tax deduction

A tax deductible is an expense that a taxpayer or business can subtract from adjusted gross income, reducing their taxable income and therefore reducing the amount of taxes owed. Governments often use tax deductibles as a way to reward people who do things that are considered beneficial to society, like charitable donations.

Early American citizenship was defined inconsistently by individual states.

See comparisons of different countries' taxation strategies

Taxes are a major revenue source for most countries, and how each government taxes citizens often reflects the country's economy. Developed countries tax at much higher rates than developing ones, and as a country grows its GDP, it also typically grows the proportional percentage of taxes it gains from its citizens.