The IRS was created by Congress in 1862 to fund the Civil War

The Internal Revenue Service did not always exist. Before 1862, the federal government had no permanent income tax and no agency to collect one. When the Civil War began, the government needed money fast. Congress passed the Internal Revenue Act of 1862, which created both an income tax and the office to collect it — originally called the Office of Internal Revenue, later renamed the IRS in 1953.

That first income tax was temporary. It was meant to last only as long as the war. After the war ended in 1865, Congress let the tax expire, and the Office of Internal Revenue shrank to almost nothing. For the next 27 years, the federal government ran on tariffs and excise taxes instead.

The income tax returned permanently in 1913, when the 16th Amendment was ratified. This amendment gave Congress the power to tax income without apportioning it among the states — a power it did not have before. That same year, the IRS was rebuilt into the agency it is today, with the authority to assess, collect, and enforce federal income tax on individuals and businesses.

Key Takeaways

  • Congress created the Office of Internal Revenue in 1862 as a temporary measure to fund the Civil War, and it was renamed the IRS in 1953.
  • The first income tax expired after the Civil War ended, and the federal government operated without one for 27 years.
  • The 16th Amendment, ratified in 1913, gave Congress permanent authority to collect income tax, and the IRS was rebuilt as a permanent agency that year.
  • The IRS is a bureau of the Department of the Treasury, meaning it operates under the Treasury Secretary and ultimately answers to the President and Congress.

How the IRS fits into the federal government

The IRS is not an independent agency. It is a bureau within the Department of the Treasury, which means it answers to the Treasury Secretary, who is appointed by the President and confirmed by the Senate. The Treasury Secretary sets broad policy, and Congress controls the IRS's budget and authority through legislation.

This structure matters because it means the IRS cannot simply decide to change tax law or create new taxes on its own. Congress writes the tax code (the Internal Revenue Code), and the IRS interprets and enforces it. The IRS can issue regulations and guidance to explain how the law works, but those regulations must stay within what Congress authorized.

The IRS also has a Commissioner, appointed by the President and confirmed by the Senate, who runs the day-to-day operations. Below the Commissioner are regional offices, service centers, and field offices that handle tax returns, audits, and collections across the country.

Why Congress created a permanent income tax system

After the Civil War, the federal government relied on tariffs — taxes on imported goods — to fund itself. But tariffs are unpredictable and can harm domestic businesses. By the early 1900s, Congress wanted a more stable source of revenue.

The problem was that the Constitution, as originally written, did not allow Congress to tax income directly. The Supreme Court ruled in 1895 that an income tax was unconstitutional without a constitutional amendment. This blocked any attempt to create a permanent income tax until the 16th Amendment passed in 1913.

Once the amendment was ratified, Congress immediately passed new tax legislation and rebuilt the IRS to enforce it. The income tax has been the federal government's largest source of revenue ever since.

What the IRS actually does

The IRS processes tax returns, collects taxes owed, and enforces the tax code. It also issues refunds when taxpayers have overpaid, maintains records of tax accounts, and investigates tax fraud. The agency employs revenue agents who conduct audits, special agents who investigate criminal tax cases, and customer service representatives who answer questions about tax law.

The IRS also publishes guidance on how to interpret the tax code. When Congress writes a law that is unclear, the IRS issues regulations and notices to explain what it means. Taxpayers and their representatives rely on this guidance to understand their obligations.

One common misconception is that the IRS writes tax law. It does not. Congress writes the tax code, and the IRS enforces it. If you disagree with a tax law, the remedy is to contact your elected representatives in Congress, not the IRS.

How the IRS has changed since 1913

The IRS of 1913 was a small operation compared to today. It had no computers, no electronic filing, and no centralized database. Tax returns were filed on paper, processed by hand, and stored in filing cabinets. Audits were conducted in person, and collections took months or years.

The agency grew dramatically during World War II, when the income tax was expanded to fund the war effort and millions of new people became taxpayers. By the 1950s, the IRS had become a large federal agency with offices in every state. The name change from "Office of Internal Revenue" to "Internal Revenue Service" in 1953 reflected this growth and its expanded role.

In recent decades, the IRS has shifted toward electronic processing. Tax returns can now be filed online, refunds are issued by direct deposit, and the IRS maintains digital records. However, the agency still processes millions of paper returns each year and still relies on manual review for complex cases and audits.

The IRS and your tax obligations

Understanding that Congress created the IRS and Congress controls it matters for your taxes. The tax rules you follow come from Congress, not from the IRS. The IRS's job is to make sure you follow those rules and to collect the taxes you owe.

If you have questions about whether you owe taxes or how much you owe, the IRS can answer them. If you disagree with a tax law itself — if you think a particular tax is unfair or unconstitutional — that is a question for Congress or the courts, not the IRS. The IRS enforces the law as written; it does not make policy decisions about whether the law should exist.

Frequently Asked Questions

Is the IRS a private company or a government agency?

The IRS is a government agency, specifically a bureau of the Department of the Treasury. It is run by the federal government and answers to Congress. It is not private and does not operate for profit.

Can the IRS change tax law on its own?

No. Congress writes tax law, and the IRS enforces it. The IRS can issue regulations to explain how the law works, but those regulations must stay within what Congress authorized. If you want to change a tax law, you must contact your elected representatives in Congress.

Who is in charge of the IRS?

The IRS is led by a Commissioner, appointed by the President and confirmed by the Senate. The Commissioner reports to the Treasury Secretary, who is also appointed by the President and confirmed by the Senate. Ultimately, Congress controls the IRS's budget and authority.

Why did the IRS start as a temporary agency?

The first income tax, created in 1862, was meant to be temporary — a way to fund the Civil War. After the war ended, Congress let it expire. The income tax did not become permanent until 1913, when the 16th Amendment was ratified and gave Congress the power to tax income indefinitely.