Most sites i've found list May 5th, or May 30th, 1868 as the first Memorial Day. But, in fact, the first celebration or observance of this tribute to veterans and war dead--
all veterans and war dead--took place on April 29, 1866, in a cemetery in Carbondale, Illinois. The memorial service and the decoration of graves was organized by John A. Logan, who had reached the rank of Major General of United States Volunteers.
When the war began, people were apprehensive about where Logan's loyalties lay. It was understood that the boys of southern Illinois would follow him, wherever he lead them. A great many people in southern Illinois were sympathetic to the Southern "cause," and in the event, a great many served with Confederate forces. Logan, a prominent member of Congress from Illinois chose to serve the Union, and was commissioned a Colonel of United States Volunteers. He helped to organize the Thirty-first Illinois Regiment of United States Volunteer Infantry. The ranks were largely filled with southern Illinois boys, with a few from Peoria, and a company from Chicago. The 31st served with distinction throughout the war. They were at Belmont, and when other regiments dissolved into looters upon reaching the Confederate camp, Logan kept his men in order. When the Confederates rallied, and attacked back into their camp, the other Yankees ran, but Logan was there with the 31st, in line with bayonets fixed, and they covered the retreat and the loading of the other regiments onto the transports under the guns of the United States Navy. At Fort Henry, the 31st did not arrive until it was all over (a freaky lucky shot from a Navy gunboat dismounted the one big gun at Fort Henry, and flooding on the Tennessee River meant the water batteries (the gun emplacements on the river bank) were flooded, so the Confederates commander surrendered to the Navy.
The 31st and the other regiments spent a miserable ten days in the ramshackle barracks which had been built from green wood for a much smaller Confederate garrison, and then marched overland in a typical mid-South, late winter ice storm to Fort Donelson on the Cumberland River. There, Grant invested the fort, which was commanded by John B. Floyd, the former Secretary of War, and Simon Buckner, a man whose military skills were much exceeded by his own opinion of them. With them was the pugnacious and fiery Gideon Pillow, a Mexican War veteran with solid military credentials, and therefore not the man in charge. (Competence seems to have been the death knell of military careers early in the war, on both sides of the lines.) Floyd and Buckner had trouble restraining Pillow, who wanted to attack the Yankees, then lying in the sodden, frozen woods outside the lines of the fort. On Valentines Day, Buckner agreed that Pillow could make the attempt, but then Pillow temporarily lost his nerve when an aide was shot down by a sniper as they were conversing. The next day, Pillow launched his attack, and initially swept all Yankee opposition before him, rolling up the right of Grant's line.
Logan and the 31st changed face, and formed a line to face Pillow's troops, and held on, even though Logan himself was shot down (he was subsequently promoted Brigadier General for his performance that day, and given a brigade). William Wallace came up with the "third" division, newly organized in the preceding few days, and Pillow's attack was stopped. Although Beford Forrest rode out with his cavalry regiment, many of them carrying an infantryman with them, and as many of the infantry as could find a horse or a mule to join them, Floyd and Buckner surrendered the rest of their command to Grant.
Logan recovered, and by early 1863 was given the command of a division, and a few weeks later, was promoted Major General of U.S. Volunteers. The 31st re-enlisted for the duration, and both Logan and the 31st had sterling records during the war. Logan took command of the XVth Corps, and then the Army of the Tennessee during the battles around Atlanta. He went home to Illinois for the 1864 election campaign--he switched from the Democratic Party to the Republicans. He rejoined the army after the elections, and in the Spring of 1865, commanded his old XVth Corps in the campaign in the Carolinas.
When Logan returned home, he was enthusiastically received by the people of southern Illinois and his veterans of the 31st Illinois. But there had been many "down home boys" who had fought in the Confederate service, and a residue of ill will. So Logan organized an observance to decorate all of the graves of the war dead in the cemetery on the east side of Carbondale, including those of the Illinois Confederates. This observance took place on April 29, 1866, a year to the day after old Joe Johnston had surrendered in Durham, North Carolina, considered the end of the war by most veterans in those days.
Logan continued to pursue his political career, serving again in the House, and then in the Senate, where he was serving at the time of his death. He also became commander of the Grand Army of the Republic, the veterans organization from the Civil War which was the equivalent of the modern American Legion. As Commander of the GAR, Logan organized the first national observance of Memorial Day in May, 1868 (i've seen both May 5th and May 30th listed as the first national observance, so take your pick).
The Confederate graves are still there, but they are down the slope from the main part of the cemetery, and the last time i saw them, more than 20 years go, they were pretty much invisible if you didn't know where to look, being overgrown, and neglected by the city crews who maintained the rest of the cemetery. There's a grave there for a boy from New Hampshire, too--who knows how he ended up there, but his people cared enough that his is a large, impressive and elegant head stone. I wonder if anyone in New Hampshire remembers that boy any longer.
I spent Memorial Day in 1975 sitting in that cemetery (i think it's Woodlawn Cemetery, but don't quote) in the rain, remembering all the boys i served with whom i've never seen since, or whom no one will ever see again. I last visited that cemetery in the late 1980s.
My grandfather served in the Great War. My mother and father served in the Second World War. My oldest brother served in the Navy, and my other brother and i served in the Army. My best wishes to all the veterans out there, and the families of those who won't be coming home to join them. I like RJB's snatch of poetry there at the beginning, which was written by a Canadian doctor, John McCrae. He died not long after writing that poem of a septic disease which he contracted while treating his fellow countrymen. There is a photograph of him that i have always loved: