Final answer:
The Whiskey Rebellion was the event that most directly challenged George Washington's ideals by testing the new federal government's ability to enforce its laws and maintain order, leading Washington to respond with federal force.
Step-by-step explanation:
The event that most directly challenged the ideals presented by George Washington was likely The Whiskey Rebellion. George Washington, who was President at the time, responded to this domestic insurrection by sending a large federal militia to suppress the rebellion in western Pennsylvania. The Whiskey Rebellion arose due to the implementation of an excise tax on distilled spirits in 1791, as part of Hamilton's financial program to stabilize the nation's finances. The rebellion directly contravened the rule of law and the authority of the federal government, challenging the ability of the government to enforce its laws and underscoring the importance of federal authority and stability, which Washington had emphasized.
While Shays's Rebellion was a significant event leading to the Constitutional Convention and inspiring fears of anarchy, it occurred under the Confederation government and so isn't the correct answer in this context. The key here is that The Whiskey Rebellion directly involved the federal government under Washington and thus challenged his administration's principles.