* 1791: The first revenue act is passed in the United States, imposing taxes on distilled spirits, carriages, refined sugar, snuff, snuff mills, bonds and slaves.
* 1794: During the so-called Whiskey Rebellion, President Washington sends troops into Pennsylvania to enforce new federal taxes.
* 1802: Under President Jefferson, the new taxes are abolished.
* 1812: The nation's first sales tax is imposed on watches, silverware and jewelry to raise money for the War of 1812.
* 1817: The new taxes are abolished. 1861: After the outbreak of the Civil War, Congress passes the Revenue Act of 1861, imposing new excise taxes and an income tax set at 3 percent of annual income over $800.
* 1862: President Lincoln signs the country's most sweeping tax bill to date. Excise taxes are imposed on playing cards, gunpowder, feathers, iron, telegrams, pianos, yachts, whiskey, legal documents, slaughtered cattle, ferry boats and advertisements. Two rates are set for the personal income tax, reflecting a person's ability to pay. Taxes are to be withheld from paychecks, and a new office, the Commissioner of Internal Revenue, is created.
* 1872: The income taxes are abolished. 1894: A tax is imposed on personal income, at a flat 2 percent rate.
* 1895: The Supreme Court rules that the new income tax is unconstitutional, saying the tax should be apportioned among the states, based on their population.
* 1898: Congress passes the Revenue Act of 1898 to raise funds for the Spanish-American War. Taxes are doubled on beer and tobacco, a user fee is imposed on federal recreation facilities and a sales tax imposed on chewing gum.
* 1902: The Revenue Act expires.
* 1909: Corporations are taxed for the first time, at a rate of 1 percent of their net income over $5,000.
* 1913: The 16th Amendment is ratified, giving the federal government broad powers to collect taxes, from any source.
* 1913: Congress imposes new income tax with progressive rates. Form 1040 is introduced.
* 1918: Congress passes the War Revenue Act, codifying all existing tax laws.
* 1932: In the midst of the Depression, Congress passes a new tax law, raising the tax rates and lowering exemption levels.
* 1935: Congress passes the Social Security Act, financed by a 1 percent tax paid by workers and employers on the first $3,000 of a worker's wages.
* 1944: A series of World War II emergency taxes becomes a permanent part of American tax law. The tax base is expanded for the first time to cover almost every American, personal exemptions are set at $500, and tax rates are set, ranging from 20 to 91 percent. Once again, taxes are withheld directly from paychecks.
* 1953: The Bureau of Internal Revenue is renamed the Internal Revenue Service.
* 1961: Congress passes a law requiring taxpayers to use their Social Security number as a tax identification number.
* 1969: Congress passes the Tax Reform Act of 1969, dramatically lowering rates.