city, seat (1788) of Clinton county, northeastern New York, U.S., on the west shore of Lake Champlain (Champlain, Lake), at the mouth of the Saranac River, 60 miles (97 km) south of Montreal, Canada. It was founded by Zephaniah Platt in 1784. During the War of 1812 (1812, War of), it was the scene of an important U.S. victory on Lake Champlain that saved New York from possible British invasion via the Hudson River valley. A British army of some 14,000 troops under Sir George Prevost (Prevost, Sir George, 1st Baronet) reached Plattsburg in a joint land and sea operation. U.S. defenders included 1,500 regulars and about 2,500 militia commanded by General Alexander Macomb, supported by a 14-ship U.S. naval squadron under Commodore Thomas Macdonough (Macdonough, Thomas). The outcome of the battle was determined on water when the British fleet was decisively defeated on September 11, 1814. Deprived of naval support, the invading army was forced to retreat. The victory at Plattsburg influenced the terms of peace drawn at the Treaty of Ghent (Ghent, Treaty of) the following December. The Macdonough Memorial commemorating the battle is in front of the city hall. The Kent-Delord House (1797) served successively as British and American headquarters and is maintained as a museum.