Memorial Day is a US federal holiday wherein the men and women who died while serving in the United States Armed Forces are remembered. The holiday, which is celebrated every year on the final Monday of May, was formerly known as Decoration Day and originated after the American Civil War to commemorate the Union and Confederate soldiers who died in the Civil War. By the 20th century, Memorial Day had been extended to honor all Americans who have died while in the military service. It typically marks the start of the summer vacation season, while Labor Day marks its end.
Many people visit cemeteries and memorials, particularly to honor those who have died in military service. Many volunteers place an American flag on each grave in national cemeteries.