The event that led to the start of the French and Indian War was the dispute over territorial claims in North America, particularly in the Ohio River Valley in the mid-18th century. The conflict arose between the British and French colonial empires, each seeking to expand their influence and control over trade routes and land. Specifically, the skirmish that escalated tensions was the 1754 confrontation at Fort Duquesne, where British colonial forces under George Washington faced French troops. As skirmishes increased and alliances formed with various Native American tribes, the war officially broke out in 1754 and lasted until 1763, significantly altering North American geopolitics.