During the Seven Years War, a worldwide conflict known as the French and Indian War in America, the British under General James Wolfe achieve a dramatic victory when they scale the cliffs over the city of Quebec, defeating the Marquis de Montcalm's French forces on the Plains of Abraham. Wolfe himself was fatally wounded during the battle, but his victory ensured British supremacy in Canada. Montcalm also suffered a mortal wound during the battle.
In the early 1750s, French expansion into the Ohio River valley repeatedly brought France into armed conflict with the British colonies. In 1756--the first official year of fighting in the Seven Years War--the British suffered a series of defeats against the French and their broad network of Native American alliances. However, in 1757, British Prime Minister William Pitt (the older) recognized the potential of imperial expansion that would come out of victory against the French and borrowed heavily to fund an expanded war effort. Pitt financed Prussia's struggle against France and her allies in Europe and reimbursed the colonies for the raising of armies in North America.
By 1760, the French had been expelled from Canada, and by 1763 all of France's allies in Europe had either made a separate peace with Prussia or had been defeated. In addition, Spanish attempts to aid France in the Americas had failed, and France also suffered defeats against British forces in India.
The Seven Years War ended with the signing of the treaties of Hubertusburg and Paris in February 1763. In the Treaty of Paris, France lost all claims to Canada and gave Louisiana to Spain, while Britain received Spanish Florida, Upper Canada, and various French holdings overseas. The treaty ensured the colonial and maritime supremacy of Britain and strengthened the 13 American colonies by removing their European rivals to the north and the south. Fifteen years later, French bitterness over the loss of most of their colonial empire contributed to their intervention in the American Revolution on the side of the Patriots.