The Fort Henry Guard's Drill Squad, doing exercises. Fort Henry is located in Kingston, Ontario, Canada on Point Henry, a strategic point located near the mouth of the Cataraqui River where it flows into the St. Lawrence River. The original fort was constructed during the War of 1812, when present-day Ontario was a British colony known as Upper Canada. The fort was constructed on the high ground of Point Henry to protect the Kingston Royal Naval Dockyard from a possible United States attack.