Memorial Day in the United States remembers and honors military personnel who died in active service to their country. Originating after the Civil War, it was initially known as Decoration Day, when people would decorate the graves of fallen soldiers. Over time, Memorial Day evolved to commemorate all American military casualties. Observed on the last Monday in May, the day is marked by ceremonies, parades, and the decoration of graves. It serves as a poignant reminder of the sacrifices made by service members and as an opportunity for reflection on the costs of war and the value of freedom.