That's what day this is -- or was. They call it "Memorial Day" now, a name already adopted as the last vestiges of the armies whose fallen once had their graves decorated and the sacrifices marked on this day: the Grand Army of the Republic and the United Confederate Veterans held their last gatherings in 1949 and 1951, respectively.
Remembrances for the dead of each side had evolved separate Decoration Days -- pragmatically in the spring, when the first large growth of flowers were available. The commemorations gradually merged, though you'll find remnants of Confederate Memorial Day still on the calendars of some southern States. One of the earliest such days was in the South, in May 1865 -- but marked Union dead, as African-American residents cleaned up and landscaped the graves of prisoners of war who had died in the prison at Washington Race Course (now Hampton Park) in Charleston, South Carolina.
By 1868, the day had attained a degree of official recognition which continued to grow in North and South alike, even as the veterans of the war that inspired it faded away.
It is a day for remembering the fallen, for remembering the price of war's prizes, a day not for arguing why or how but honoring those who went, did their duty -- and never returned. Spare them a thought. Tend their graves this one day, at least.
8 months ago