Old Fort Erie, also known as Fort Erie, or the Fort Erie National Historic Site of Canada, was the first British fort to be constructed as part of a network developed after the Seven Years' War (known as "the French and Indian War" in the colonies) was concluded by the Treaty of Paris (1763), at which time France ceded its territories east of the Mississippi River (all of New France) to Great Britain. The installation is located on the southern edge of what is now the Town of Fort Erie, Ontario, directly across the Niagara River from Buffalo, New York, United States.