Final answer:
The British lost significant battles in New York at Fort Duquesne, Fort Oswego, and Fort William Henry during the French and Indian War, but ultimately won the war with the Treaty of Paris in 1763.
Step-by-step explanation:
The British experienced numerous setbacks during the early stages of the French and Indian War. Among the significant losses was the defeat at Fort Duquesne in 1755, where the British, under General Edward Braddock's command, were ambushed by the French and their Native American allies, resulting in a disastrous defeat for the British and the death of General Braddock. Despite this early loss and others at Fort Oswego and Fort William Henry, the tide of war eventually turned, culminating in the signing of the Treaty of Paris in 1763 which marked the end of French power in North America and signaled the rise of the British Empire as a truly global force.
While the French and British fleets engaged in several significant encounters, the reference to a battle in New York during the French and Indian War, where the British lost, could specifically involve the Battle of Fort Oswego (1756) or Fort William Henry (1757), both of which were British defeats. The culmination of the conflict saw British colonial forces gaining confidence despite initial losses, as demonstrated in later battles like that of Breed's Hill, wherein the British technically won but suffered heavy casualties that ultimately weakened their position.