Memorial Day (previously, but now seldom, called Decoration Day is a federal holiday in the United States for honoring and mourning the military personnel who have died while serving in the United States Armed Forces.
The holiday is now observed on the last Monday of May, having been 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.
Memorial Day is also considered the unofficial start of summer in the United States, while Labor Day, the first Monday of September, marks the unofficial start of autumn.
Two other days celebrate those who have served or are serving in the U.S. military: Veterans Day, which honors those who have served in the United States Armed Forces, and Armed Forces Day, an unofficial U.S. holiday (earlier in May) for honoring those currently serving in the armed forces.