Final answer:
The British were defeated in the Battle of Fort Duquesne during the French and Indian War, also known as the Seven Years' War.
Step-by-step explanation:
The British are defeated in the Battle of Fort Duquesne during the French and Indian War. This war, also known as the Seven Years' War, was fought between Britain and France in America from 1754 to 1763. The British originally struggled in the war, but eventually turned the tide and gained victory over the French, leading to their control over North America.