Each year, the last Monday of May is observed to honor the men and women who died while serving in the United States military. Formerly known as Decoration Day, this tradition originated following the Civil War and became a federal holiday known as Memorial Day in 1971. Some dispute when the first remembrance occurred, but one of the earliest Memorial Day commemorations on record was organized by a group of former slaves in Charlestown, South Carolina shortly after the Confederacy surrendered in 1865.