May 2008: Motorbikes of veterans and well-wishers stand parked on Memorial Day in Washington, DC. Memorial Day is a federal holiday in the United States for remembering the people who died while serving in the country’s armed forces. The holiday is observed every year on the last Monday of May. Many people visit cemeteries and memorials, particularly to honour those who have died in military service. Many volunteers place an American flag on each grave in national cemeteries.