Patriots’ Day is observed in several U.S. states, including Massachusetts, Maine, Connecticut, North Dakota, and Wisconsin, on the third Monday in April. This holiday commemorates the first battles of the American Revolutionary War, specifically the Battles of Lexington and Concord, which occurred on April 19, 1775. The observance originated in 1894 when the Lexington Historical Society proposed April 19 as Lexington Day, leading to a compromise that established Patriots’ Day. Celebrations typically include re-enactments of the battles in Arlington, Concord, and Lexington, along with guided tours of historic sites. A significant event associated with this day is the Boston Marathon, the world's oldest annual marathon, which has been held since 1897, except for 2020 and 2021 due to the COVID-19 pandemic. While Patriots’ Day is celebrated in these states, it should not be confused with Patriot Day, which is observed nationwide on September 11 to honor the victims of the 9/11 terrorist attacks.