The federal income tax began in 1861 as a temporary war measure

The United States first introduced a federal income tax in 1861 to fund the Civil War. Congress passed it as a temporary tax that was supposed to expire when the war ended. It was not a permanent part of the tax system at that time — it was meant to be a short-term solution to raise money for military operations.

The tax applied only to people with higher incomes, so most Americans did not pay it. The rates were low by modern standards, and the number of people who actually owed income tax was small. After the Civil War ended in 1865, the tax remained in place for another decade before Congress let it expire in 1872.

Key Takeaways

  • The federal income tax started in 1861 as a temporary measure to pay for Civil War expenses, not as a permanent tax system.
  • The first income tax only affected people earning above a certain threshold, so the vast majority of Americans did not pay it.
  • Congress allowed the original income tax to expire in 1872, and no federal income tax existed for the next 17 years.
  • The income tax returned in 1894 but was struck down by the Supreme Court in 1895 as unconstitutional.
  • The 16th Amendment, ratified in 1913, gave Congress the permanent legal power to collect income tax without apportioning it among the states.

Why Congress created the income tax during the Civil War

The Civil War was expensive, and the federal government needed money fast. Before 1861, the government relied mainly on tariffs — taxes on imported goods — and excise taxes on specific items like alcohol and tobacco. These sources were not bringing in enough revenue to pay for a massive war effort.

An income tax seemed like a way to reach people with money directly. Congress set a threshold so that only people earning above a certain amount had to pay. This made it politically easier to pass, because most voters would not be affected. The tax was framed as temporary and necessary, not as a permanent change to how the country would be funded.

The income tax disappeared and then returned

After the Civil War ended, the income tax stayed on the books for several more years because the government still needed the revenue. But by 1872, Congress allowed it to expire. For the next 17 years, there was no federal income tax at all.

In 1894, Congress tried to bring the income tax back. This time it was not tied to a war — lawmakers wanted a new source of revenue. However, the Supreme Court ruled in 1895 that this income tax was unconstitutional. The Court said Congress could not tax income from property without dividing the tax burden among the states in a specific way. This ruling blocked the income tax until the Constitution itself was changed.

The 16th Amendment made the income tax permanent and constitutional

In 1913, the 16th Amendment was ratified. It gave Congress the power to collect income tax directly from people without having to divide it among the states. This amendment removed the legal barrier that the Supreme Court had created in 1895.

Once the 16th Amendment was in place, Congress passed a new income tax law that same year. This income tax has remained part of the federal tax system ever since. The rates, the number of people who pay it, and the rules around it have all changed many times over the past 110 years, but the income tax itself has been a permanent feature of federal taxation since 1913.

How the income tax has changed since 1913

The income tax that started in 1913 looked very different from what exists today. The original tax rates were low — the top rate was only 7 percent. Very few people had to pay it because the threshold for owing tax was high. The tax was designed mainly to reach wealthy individuals and corporations.

During World War I and World War II, income tax rates rose sharply to pay for military spending. After World War II, the tax remained a major source of federal revenue. Over the decades, Congress has changed the tax rates, the number of tax brackets, the deductions people can claim, and the income thresholds that determine who pays. The income tax has grown from a tax that affected only the wealthy to a tax that millions of middle-income Americans now pay.

State income taxes developed separately from the federal tax

While the federal government was developing its income tax system, individual states were also creating their own income taxes. States did not need a constitutional amendment to do this — they had the power to tax income within their borders from the beginning. However, most states did not adopt income taxes until the 20th century.

Wisconsin was the first state to pass an income tax, in 1911. Other states followed gradually. Today, most states have their own income tax systems, though a few states do not tax income at all. State income taxes are separate from the federal income tax, and the rates and rules vary widely from state to state.

Why the income tax became the main source of federal revenue

When the income tax returned in 1913, it was one of several sources of federal revenue. Tariffs and excise taxes still brought in significant money. But over time, the income tax grew to become the largest source of federal revenue. This happened partly because Congress raised income tax rates during wars and then did not lower them afterward, and partly because the economy grew and more people earned higher incomes.

By the mid-20th century, the income tax was funding most of the federal government's operations. Today, individual income taxes and payroll taxes (which fund Social Security and Medicare) together make up the vast majority of federal revenue. The tariffs that once dominated federal funding now play a much smaller role.

Frequently Asked Questions

Did everyone have to pay income tax when it started in 1861?

No. The 1861 income tax only applied to people earning above a certain threshold, which was fairly high at the time. Most Americans earned less than that amount and did not owe any income tax. The tax was designed to reach people with higher incomes.

Why did the Supreme Court strike down the 1894 income tax?

The Supreme Court ruled in 1895 that the income tax was unconstitutional because it was a direct tax on property. The Constitution required direct taxes to be divided among the states based on population. Congress could not collect an income tax without following this rule — until the 16th Amendment changed the Constitution in 1913.

What did the 16th Amendment actually say?

The 16th Amendment gave Congress the power to collect income taxes without apportioning them among the states. This removed the constitutional barrier that had blocked the 1894 income tax. It did not create the income tax itself — it straightforward gave Congress the legal authority to create one.

Were income tax rates always as high as they are today?

No. When the income tax started in 1913, the top rate was only 7 percent. Rates rose sharply during World War I and World War II and stayed high afterward. The rates have changed many times since then, sometimes rising and sometimes falling, depending on what Congress decided.

Do all states have income taxes?

Most states have income taxes, but not all. A few states do not tax income at all. States developed their own income tax systems separately from the federal system, and each state makes its own decisions about whether to have an income tax and what the rates should be.