The Whiskey Rebellion was an insurrection in 1794 by settlers in the Monongahela Valley in western Pennsylvania who fought against a federal tax on liquor and distilled drinks.

The ineffective government of the United States under the Articles of Confederation was replaced by a stronger federal government under the United States Constitution in 1788. This new government inherited a huge debt from the American Revolutionary War. One of the steps taken to pay down the debt was a tax imposed in 1791 on distilled spirits.

Large producers were assessed a tax of six cents a gallon. However, smaller producers, most of whom were farmers in the more remote western areas, were taxed at a higher rate of nine cents a gallon. These Western settlers were short of cash to begin with, and lacked any practical means to get their grain to market other than fermenting and distilling it into relatively portable distilled spirits. From Pennsylvania to Georgia, the western counties engaged in a campaign of harassment of the federal tax collectors. In the summer of 1794, George Washington and Alexander Hamilton, remembering Shays' Rebellion from just eight years before, decided to make Pennsylvania a testing ground for federal authority. Washington ordered federal marshals to serve court orders requiring the tax protesters to appear in federal district court. By August of 1794, the protests became dangerously close to outright rebellion and on August 7 several thousand armed settlers gathered near Pittsburgh, Pennsylvania. Washington then invoked the Militia Law of 1792 to summon the militias of several states. A force of 13,000 men was organized, roughly the size of the entire army in the Revolutionary War. Under the personal command of Washington, Hamilton, and Revolutionary War hero Henry "Lighthorse Harry" Lee the army marched to Western Pennsylvania and quickly suppressed the revolt. Two leaders of the revolt were convicted of treason, but pardoned by Washington.

This response marked the first time under the new Constitution that the federal government had used strong military force to exert authority over the nation's citizens. It also was the only time that a sitting President would personally command the military in the field.

The whiskey tax was repealed in 1802, never having been collected with much success.