responsibilities, advances in technology since the Constitution's adoption have increased presidential power. Where formerly ambassadors were vested with significant power to independently negotiate on behalf of the United States, presidents now routinely meet directly with leaders of foreign countries. Commander-in-chief One of the most important of executive powers is the president's role as commander-in-chief of the United States Armed Forces. The power to declare war is constitutionally vested in Congress, but the president has ultimate responsibility for the direction and disposition of the military. The exact degree of authority that the Constitution grants to the president as commander-in-chief has been the subject of much debate throughout history, with Congress at various times granting the president wide authority and at others attempting to restrict that authority. The framers of the Constitution took care to limit the president's powers regarding the military; Alexander Hamilton explained this in Federalist No. 69: In the modern era, pursuant to the War Powers Resolution, Congress must authorize any troop deployments longer than 60 days, although that process relies on triggering mechanisms that have never been employed, rendering it ineffectual. Additionally, Congress provides a check to presidential military power through its control over military spending and regulation. Presidents have historically initiated the process for going to war, but critics have charged that there have been several conflicts in which presidents did not get official declarations, including Theodore Roosevelt's military move into Panama in 1903, the Korean War, the Vietnam War, and the invasions of Grenada in 1983 and Panama in 1989. The amount of military detail handled personally by the president in wartime has varied greatly. George Washington, the first U.S. president, firmly established military subordination under civilian authority. In 1794, Washington used his constitutional powers to assemble 12,000 militia to quell the Whiskey Rebellion—a conflict in western Pennsylvania involving armed farmers and distillers who refused to pay an excise tax on spirits. According to historian Joseph Ellis, this was the "first and only time a sitting American president led troops in the field", though James Madison briefly took control of artillery units in defense of Washington, D.C., during the War of 1812. Abraham Lincoln was deeply involved in overall strategy and in day-to-day operations during the American Civil War, 1861–1865; historians have given Lincoln high praise for his strategic sense and his ability to select and encourage commanders such as Ulysses S. Grant. The present-day operational