[58] Forbes nevertheless made Washington a brevet brigadier general and gave him command of one of the three brigades that would assault the fort. The French abandoned the fort and the valley before the assault was launched; Washington saw only a friendly fire incident which left 14 dead and 26 injured. The war lasted another four years, and Washington resigned his commission and returned to Mount Vernon.[59]
Under Washington, the Virginia Regiment had defended 300 miles (480 km) of frontier against twenty Indian attacks in ten months.[60] He increased the professionalism of the regiment as it increased from 300 to 1,000 men, and Virginia's frontier population suffered less than other colonies. Some historians have said this was Washington's "only unqualified success" during the war.[61] Though he failed to realize a royal commission, he did gain self-confidence, leadership skills, and invaluable knowledge of British military tactics. The destructive competition Washington witnessed among colonial politicians fostered his later support of a strong central government.