Memorial Day (originally known as Decoration Day is a federal holiday in the United States for mourning the U.S. military personnel who have died while serving in the United States armed forces. It is observed on the last Monday of May. It was formerly observed on May 30 from 1868 to 1970.
Many people visit cemeteries and memorials on Memorial Day to honor and mourn those who died while serving in the U.S. military. Many volunteers place an American flag on graves of military personnel in national cemeteries.