in July of 1760 (the last Naval battle of the Seven Years War) is what really sealed the fate of New France. I live about 2 miles from where the battle took place and find artifacts and stuff with my metal detector. If the French had won that battle they would have been able to supply the troops in Quebec City where they were at a standstill and waiting. With both sides looking east down the St. Lawrence River for troops and supplies, they waited and since the English defeated the French here, they were able to supply their troops win. Montreal fell after that and the rest is history.