Overview

The largest bureau in the Treasury, the Internal Revenue Service (better known as the IRS) employs over 100,000 workers. This large workforce collects nearly $2.4 trillion in annual taxes, processing more than 224 million forms from U.S. citizens each year. Created to collect income taxes in order to fund the Civil War, the IRS originally went by the name of the Bureau of Internal Revenue.

By the 1920s, the IRS also tackled enforcement of prohibition laws. Now the IRS determines the amount owed by taxpayers and collects on taxes levied nationwide in order to provide revenue for the federal government. The organization collects income, excise, estate and the employment taxes that help fund the Social Security System.