The 16th Amendment, Authorizing Federal Income Tax, Is Ratified – This Day in History

On February 3, 1913, the Sixteenth Amendment of the United States Constitution was ratified. It stands as one of the most transformative changes in American fiscal history, and it granted Congress the explicit authority to levy and collect income taxes on individuals and corporations without apportioning those taxes among the states based on population. This change resolved a major constitutional hurdle that had long constrained federal taxing power.

When the Constitution was originally written, Article I empowered Congress to “lay and collect Taxes, Duties, Imports, and Excises,” but direct taxes—such as a tax directly on income—had to be apportioned among the states according to population. This meant any federal income tax would have to be divided in proportion to each state’s share of the national population, a requirement that proved impractical and unfair for a national tax system. The short-lived income tax enacted during the Civil War under the Revenue Act of 1861 was repealed in 1872, and later attempts at income taxation faced legal obstacles. In 1894, Congress passed a tax on income as part of the Wilson-Gorman Tariff Act, but the Supreme Court struck it down in Pollock v. Farmers’ Loan & Trust Company (1895), ruling that the unapportioned tax on incomes from property was a direct tax and thus unconstitutional under the original apportionment rules.

In response, reformers and lawmakers sought a constitutional amendment. After years of debate during the Progressive Era, when many Americans sought reforms to reduce economic inequality and modernize government, Congress proposed the Sixteenth Amendment in 1909. By February 1913, it had been ratified by the requisite three-quarters of state legislatures, formally altering the Constitution. The Amendment’s text states that Congress “shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.”

The impact of the Sixteenth Amendment was profound. It gave the federal government a reliable and flexible source of revenue that could grow with the nation’s economy. Within weeks of ratification, Congress enacted the Revenue Act of 1913, which implemented a federal income tax system. Over the twentieth century, income tax revenues became the backbone of the U.S. government’s finances, funding everything from infrastructure and education to social programs and national defense.

Beyond its fiscal effects, the Amendment reshaped the relationship between citizens and the federal government. Empowering Congress to collect taxes directly from a broad base of incomes, it enabled the expansion of federal roles and responsibilities. An income tax system also created mechanisms for progressive taxation—where higher earners pay a larger share—reflecting broader social goals of equity and shared civic investment.

Today, the Sixteenth Amendment remains central to the modern U.S. government’s operation. While it has been the subject of political debate and occasional calls for repeal, its fundamental role in enabling federal revenue and shaping twentieth- and twenty-first-century governance is undeniable.