The Big Runaway was a mass evacuation in June and July 1778 of settlers from the frontier areas of north central Pennsylvania during the American Revolutionary War. A major campaign by Loyalists and Native Americans allied with the British devastated the small communities on the northern and western branches of the Susquehanna River, prompting local militia leaders to order the evacuation. Most of the settlers relocated to Fort Augusta at modern-day Sunbury at the confluence of the North and West Branches of the Susquehanna River, while their abandoned houses and farms were all burnt.