The Battles of Lexington and Concord on April 19, 1775, were the first major military actions between the British Army and Patriot militias from British America's Thirteen Colonies during the American Revolutionary War. The opposing forces fought day-long running battles in Middlesex County in the Province of Massachusetts Bay, in the towns of Lexington, Concord, Lincoln, Menotomy, and Cambridge.

The siege of Boston was the opening phase of the American Revolutionary War. In the siege, American patriot militia led by newly-installed Continental Army commander George Washington prevented the British Army, which was garrisoned in Boston, from moving by land. Both sides faced resource, supply, and personnel challenges during the siege. British resupply and reinforcement were limited to sea access, which was impeded by American vessels. The British ultimately abandoned Boston after eleven months, moving their troops and equipment north to Nova Scotia.