The Sixteenth Amendment Made Income Tax Constitutional Again

The federal income tax was reinstated in 1913 because the Sixteenth Amendment to the Constitution, ratified that year, gave Congress the power to tax income without apportioning it among the states. Before 1913, an 1895 Supreme Court ruling had struck down an earlier income tax as unconstitutional. The amendment reversed that decision and opened the door for the government to collect income tax directly from individuals and businesses.

This was not a casual policy shift. The amendment required approval from three-fourths of the states — a high bar that took years of political effort. Once it passed, Congress moved quickly to write the first permanent income tax law, which took effect in 1913 under President Woodrow Wilson.

Key Takeaways

  • The Supreme Court ruled in 1895 that income tax was unconstitutional because it was a "direct tax" that had to be divided among states based on population.
  • The Sixteenth Amendment, ratified in 1913, removed that requirement and gave Congress the power to tax income without apportionment.
  • The government needed a new revenue source because tariffs alone could not fund federal operations and military spending.
  • The 1913 income tax started at 1 percent on high earners and was designed to shift the tax burden away from working people.

The 1895 Supreme Court Decision That Blocked Income Tax

In 1894, Congress passed an income tax to help pay for government operations. The law taxed income from property, investments, and wages. Within a year, the Supreme Court ruled in Pollock v. Farmers' Loan & Trust Co. that this tax was unconstitutional.

The Court's reasoning turned on the Constitution's language about "direct taxes." The Constitution says direct taxes must be apportioned — divided among states based on their population. An income tax, the Court decided, was a direct tax, and Congress had not apportioned it. Therefore, it violated the Constitution. This ruling wiped out the 1894 tax and blocked any similar attempt for nearly two decades.

The decision left the federal government with a problem: it needed money, and tariffs — taxes on imported goods — were its main source of revenue. As the country grew and military spending increased, tariff revenue alone became insufficient.

Why the Government Needed a New Revenue Source

By the early 1900s, the federal government faced rising costs. The military was expanding, the Panama Canal project was underway, and Congress was spending more on infrastructure and services. Tariffs brought in revenue, but they were unpopular with many Americans because they raised prices on everyday goods.

An income tax offered an alternative. Unlike tariffs, which affected everyone who bought imported goods, an income tax could be targeted at people with higher earnings. Supporters argued it was fairer because it asked those with more money to pay more. This argument helped build political support for changing the Constitution.

Business and labor groups split on the issue. Some business owners opposed an income tax, while others saw it as preferable to higher tariffs. Labor unions and progressive politicians supported it as a way to shift the tax burden away from working people who paid tariffs on goods they needed.

The Sixteenth Amendment Campaign and Ratification

The push to overturn the 1895 ruling began almost when ready. Supporters drafted the Sixteenth Amendment, which stated straightforward: "The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States." This language removed the apportionment requirement that had killed the 1894 tax.

Congress approved the amendment in 1909. Ratification by the states took longer. The amendment needed approval from 36 of the 48 states then in the Union. By February 1913, enough states had voted yes, and the amendment became part of the Constitution. Wyoming was the final state needed to reach the three-fourths threshold.

The ratification process revealed regional divisions. Southern and Western states, which had fewer wealthy residents and stood to benefit from shifting taxes away from tariffs, voted yes. Some Northern industrial states were slower to ratify, though most eventually did.

The First Permanent Income Tax Law of 1913

With the Sixteenth Amendment in place, Congress passed the first permanent federal income tax in October 1913 as part of the Underwood Tariff Act. The law taxed income above a certain threshold — initially $3,000 for individuals and $4,000 for married couples, amounts that put most working people outside the tax base.

The tax rate started at 1 percent on income above the threshold and rose to 7 percent on very high incomes. This was a progressive tax — the rate increased as income increased. The law also taxed corporate income at a flat 1 percent rate.

The 1913 tax was narrow by later standards. Only about 3 percent of the population owed income tax. The government expected it to bring in roughly $80 million per year, a significant sum at the time. Most Americans paid nothing because their income fell below the threshold.

How the Income Tax Changed Over Time

The income tax that began in 1913 was modest, but it grew. During World War I, Congress raised rates and lowered the income threshold to fund military spending. By the 1920s, income tax had become the government's largest source of revenue, surpassing tariffs.

The tax base expanded during the Great Depression and World War II. Thresholds dropped, and more people owed tax. By the 1940s, income tax had become a mass tax affecting millions of Americans, not just the wealthy. This transformation happened gradually through wartime needs and changing policy, not through a single decision in 1913.

The 1913 reinstatement was the legal foundation, but the income tax system Americans know today took shape over decades of war, recession, and political choice.

Frequently Asked Questions

Why did the Supreme Court say the 1894 income tax was unconstitutional?

The Court ruled that income tax was a "direct tax" under the Constitution, and direct taxes must be apportioned among states based on population. Congress had not apportioned the 1894 tax, so it violated the Constitution. The Sixteenth Amendment removed this requirement.

Did everyone have to pay the 1913 income tax?

No. The 1913 tax only applied to income above $3,000 for individuals and $4,000 for married couples. Most working people earned less than that, so they paid no federal income tax. Only about 3 percent of the population owed tax in 1913.

How much money did the 1913 income tax bring in?

The government expected the 1913 income tax to raise roughly $80 million per year. This was a significant amount at the time and helped reduce the government's dependence on tariffs. The actual revenue varied year to year based on economic conditions and changes to the tax law.

Could Congress have raised income tax without the Sixteenth Amendment?

No. The 1895 Supreme Court ruling blocked income tax unless it was apportioned among states. Apportionment would have made the tax impractical — it would have required dividing the tax burden based on state population rather than individual income. The amendment was necessary to make a workable income tax possible.

When did income tax become the main source of federal revenue?

Income tax surpassed tariffs as the government's largest revenue source during World War I, when Congress raised rates and lowered the income threshold to fund military spending. By the 1920s, income tax was clearly the dominant source, and it has remained so ever since.