Early 1776, the city of Boston had become the focal point of agrinding strategic stalemate between the Continental Army and the British garrison under General William Howe. Since the battles of Lexington and Concord in April 1775, American forces had maintained a loose but effective siege around the city, bottling up roughly 6,000 British regulars and severalthousand Loyalist civilians within a narrow peninsula connected to the mainland by a single, fortified neck. Neither side possessed the decisive advantage needed to break the deadlock. That is until the Americans received the heavy artillery and a well-defended position.