Complex sentence: Gunfire between Patriot scouts and the camp guards alerted Boyd to the situation, who formed a defensive line near the camp's rear, and advanced with a force of 100 men to oppose Pickens at a crude breastwork made of fencing and fallen trees.
Split into simpler sentences: Gunfire between Patriot scouts and the camp guards alerted Boyd to the situation. Boyd formed a defensive line near the camp's rear, and advanced with a force of 100 men to oppose Pickens at a crude breastwork made of fencing and fallen trees.