In the War of 1812, the United States confronted the greatest naval power in the world, Great Britain. Sometimes called the Second War of Independence, the war began because of trade restrictions Britain imposed on America and France during the Napoleonic Wars.
By 1814, the Brits had taken hold of Washington, D.C., burning the White House as well as the Capitol and other buildings, in retaliation for burnings of Canadian buildings by U.S. troops. (As a colony of Great Britain, Canada was swept into the war, too.)
Lake Champlain came into play when Canada's Commander in Chief, Lieutenant-General Sir George Prévost, was authorized to launch offensives into American territory. Prévost opted to attack via the Richelieu River into Lake Champlain and advanced down the western side of the lake to the American position at Plattsburgh, New York.
Despite American attempts to slow the British, the Brits continued to advance and skirmish. The Americans withdrew to Plattsburgh Bay, forcing the British to engage at close range. Meanwhile, Master Commandant Thomas Macdonough prepared the American forces to fight at anchor.