Washington is likely never burned, as the siege of Baltimore never happens... so the Americans will have to find a new anthem somewhere else. New Orleans probably doesn't happen or the Penobscot expedition (depending on when Napoleon wins). Honestly, the only real difference in the War of 1812 is that Prevost doesn't attack Plattsburg. Lundy's Lane might end differently too (but I don't think it will have any real outcome on the war).