Memorial Day Originally called Decoration Day, it was formalized by a “Memorial Day Order” . It was first widely observed on May 30, 1868 to commemorate the sacrifices of Civil War soldiers, by proclamation of Gen. John A. Logan of the Grand Army of the Republic, an organization of former Union sailors and soldiers. From 1868 to 1970, it was observed on May 30. Since 1971, it is observed on the last Monday of May.