Memorial Day is more than just hot dogs, barbecues, and parades on the last Monday of May. The national holiday was established to honor those who have died in American wars. Memorial Day was originally called Decoration Day. It originated during the American Civil War, when citizens would place flowers on the graves of those who had been killed in battle. After the Civil War, many cities held observances in May for the families of both Confederate and Union soldiers who had died serving their cause. In 1868 John A. Logan, the commander in chief of the Grand Army of the Republic, an organization of Union veterans, promoted a national holiday on May 30 “for the purpose of strewing with flowers or otherwise decorating the graves of comrades who died in defense of their country during the late rebellion.” After World War I, as the day came to be observed in honor of those who had died in all U.S. wars, its name changed from Decoration Day to Memorial Day. Since 1971 Memorial Day has been observed on the last Monday in May. It is observed with the laying of a wreath at the Tomb of the Unknowns in Arlington National Cemetery in Arlington, Virginia, and by religious services, parades, and speeches nationwide.
Information from: britannica