Fort Ontario is an American historic bastion fort situated by the City of Oswego in Oswego County, New York. It is owned by the state of New York and operated as a museum known as Fort Ontario State Historic Site. Geography and early history Fort Ontario is located on the east side of the Oswego River on high ground overlooking Lake Ontario. Fort Ontario was one of several forts erected by the British to protect the area around the east end of Lake Ontario. The original Fort Ontario was erected in 1755, during the French and Indian War, in order to bolster defenses already in place at Fort Oswego on the opposite side of the river. At that time its name was the "Fort of the Six Nations," but the fort was destroyed by French forces during the Battle of Fort Oswego in 1756 and rebuilt by British forces in 1759. At the conclusion of Pontiac's War, Pontiac urged moderation and agreed to travel to New York, where he made a formal treaty with William Johnson at Fort Ontario on July 25, 1766. During the American Revolutionary War, a detachment from the 3rd New York Regiment destroyed the fort in July, 1778, after the British abandoned it. The British returned and rebuilt the fort in 1782. There was an aborted attack on the fort by Colonel Marinus Willet in 1783. The British held the fort after the war was over until 1796 after the signing of Jay's Treaty. Nineteenth century The fort was attacked and destroyed by British forces during the War of 1812 in the year 1814. After a period of disuse, new construction was undertaken in part because of tensions with Great Britain as well as to check smuggling activities between Canada and the United States. During the American Civil War the new construction began at the fort because of fear of British help from Canada to the Confederacy. After the American Civil War it held Company F, 42nd Infantry which consisted of wounded soldiers from the war that had reenlisted in the U.S. Army. Although the fort remained a military base, the fort itself fell into ruin, since funds were used to create more modern quarters outside the fort. Recent When the United States entered World War I in April 1917, the fort was repurposed as a military hospital, known as General Hospital No. 5. The facility