The "Castle" of Fort Niagara was built by the French in 1726, approximately on the site occupied by La Salle in 1678 and Denonville in 1687. Taken by the British in 1759, it was held by them as a base of warfare against the American frontiers during the War of the Revolution. It was first occupied by the United States on Aug. 11, 1796, retaken by the British on Dec. 19, 1813, and finally came under the flag of the United States of America on May 22, 1815.