When you are at the beach at Niagara On the Lake in Canada, you can look directly across the Niagara River and see the United States. Here as the Niagara River enters Lake Ontario is Fort Niagara on the U.S.A. side. This was originally a French fort taken over by the United States. In the War of 1812 between the United Kingdom and the United States there was a lot of fighting here between Fort George on the Canadian side and Fort Niagara on the US side. The forts were just across the river from each other and lobbed cannonballs back and forth.