Why did the Americans withdraw in the Battle of Bunker Hill?

The Americans withdrew during the Battle of Bunker Hill primarily due to a lack of ammunition and reinforcements. Despite inflicting significant casualties on British forces, the colonial troops were outnumbered and faced intense pressure as the British launched multiple assaults. As their supplies dwindled and the British advanced, the American forces made the strategic decision to retreat. This withdrawal, while a tactical setback, demonstrated the resolve and effectiveness of the colonial fighters, shaping future engagements in the Revolutionary War.