What was the main factor leading to the whiskey rebellion?

The Whiskey Rebellion occurred in response to the U.S. government's decision, in 1791, to impose a tax on whiskey and other spirits. This was the very first federal tax imposed on the newly minted United States; the resulting revenue was intended to help pay the nation's remaining debt from the America Revolution, in which the former American colonies won their freedom from Great Britain. The rebellion was centered in western Pennsylvania, where grain farmers often distilled their excess grain crops into liquor. Many of these farmers were also veterans of American Revolution, and they believed they were rebelling against the very idea—taxation without representation—that they had fought against during the war against the British. It's important to understand that at this time, there was very little, other than the popularity of President George Washington, holding the disparate and far-flung states together and that citizens of the new United States were not yet used to seeing themselves as one nation. Therefore, they did not necessarily look at their Congressional representatives as fully representing their local interests. Washington did not hesitate in squashing the rebellion—even riding at the head of the Army—and this action helped to define federal power in the early days of the republic.