The keyword term "Patriots' Day" functions as a proper noun. It is a state holiday observed on the third Monday of April in Massachusetts, Maine, and Wisconsin, commemorating the anniversary of the Battles of Lexington and Concord. These battles, fought on April 19, 1775, were the first military engagements of the American Revolutionary War and marked the outbreak of open armed conflict between the Kingdom of Great Britain and its thirteen colonies in America.
The historical events commemorated by the holiday began with the midnight rides of Paul Revere and other couriers who warned colonial minutemen of the approaching British forces. The British objective was to seize a colonial arms cache in Concord. The first shots were fired at dawn in Lexington, Massachusetts, followed by a larger confrontation at Concord's North Bridge, famously referenced as the "shot heard 'round the world." The day's observances often include historical reenactments of these events, particularly in Lexington and Concord. The most prominent modern-day event associated with the holiday is the running of the Boston Marathon, which has been held on Patriots' Day every year since 1897.
It is crucial to distinguish this regional holiday from the national observance of Patriot Day, which occurs on September 11th each year to remember the victims of the 2001 terrorist attacks. Patriots' Day specifically celebrates the dawn of the American Revolution and holds significant cultural importance in New England as a celebration of liberty, civic responsibility, and the start of the nation's fight for independence.