Memorial Day in the U.S. is a federal holiday dedicated to honoring and remembering the men and women who have died in military service to the country. It is observed on the last Monday in May, originally established as Decoration Day following the Civil War. The day is marked by various traditions, including visiting cemeteries and memorials, placing flags on graves, and conducting ceremonies to honor fallen soldiers. Over the years, Memorial Day has evolved to also recognize all American military personnel who have sacrificed their lives in conflicts, making it a poignant occasion for reflection and gratitude.