The Battles of Lexington and Concord were the first military engagements of the American Revolutionary War. They were fought on April 19, 1775, in Middlesex County, Province of Massachusetts Bay, within the towns of Lexington, Concord, Lincoln, Menotomy (present-day Arlington), and Cambridge, near Boston. The battles marked the outbreak of open armed conflict between the Kingdom of Great Britain and its thirteen colonies in the mainland of British North America.
About 700 British Army regulars, under Lieutenant Colonel Francis Smith, were given secret orders to capture and destroy military supplies that were reportedly stored by the Massachusetts militia at Concord. Through effective intelligence gathering, Patriot colonials had received word weeks before the expedition that their supplies might be at risk, and had moved most of them to other locations. They also received details about British plans on the night before the battle, and were able to rapidly notify the area militias of the military movement.
The first shots were fired just as the sun was rising at Lexington. The militia were outnumbered and fell back, and the regulars proceeded on to Concord, where they searched for the supplies. At the North Bridge in Concord, several hundred militiamen fought and defeated three companies of the King's troops. The outnumbered regulars fell back from the Minutemen after a pitched battle in open territory.
More Minutemen arrived soon thereafter and inflicted heavy damage on the regulars as they marched back towards Boston. Upon returning to Lexington, Smith's expedition was rescued by reinforcements under Hugh, Earl Percy. A combined force of about 1,700 men marched back to Boston under heavy fire in a tactical withdrawal and eventually reached the safety of Charlestown. The accumulated militias blockaded the narrow land accesses to Charlestown and Boston, starting the Siege of Boston.