Minute Man National Historical Park was the starting place of the American Revolution, where citizens willing to risk their lives for the ideals of liberty and self-determination were instrumental in the formation of the American identity. The park preserves sites where Colonial militia men and British soldiers clashed on April 19, 1775. A force of 700 British soldiers left Boston to seize military supplies stockpiled in Concord, but alarm riders alerted the countryside, and militia companies assembled in area towns, ready to defend their communities and liberties if necessary. After brief battles at Lexington Green at 5:00 a.m. and Concord’s North Bridge at 9:30 a.m., fighting escalated along the Battle Road. As the British troops marched back toward Boston, militia companies poured in, and by afternoon nearly 4,000 Colonists unleashed an incessant fire upon the British soldiers. At the end of the day, the Colonists surrounded and laid siege to Boston, and the Revolutionary War had begun. At the North Bridge, three companies of British Regulars, about 96 men, guarding the bridge opened fire upon 400 Colonists advancing from the opposite side. Major John Buttrick of Concord then issued the command, “Fire fellow soldiers, for God’s sake fire!” For the first time, Colonists were ordered to fire upon the army of their King, and for the first time they killed British soldiers. Ralph Waldo Emerson later immortalized this event in his 1837 poem The Concord Hymn as “the shot heard round the world.”