From the What So Proudly We Hail website:
On May 30, 1868, a crowd of 5,000 gathered at Arlington National Cemetery for the first Decoration Day exercises. Before strewing flowers upon the graves of the dead, the crowd listened to an address by James A. Garfield (1831–81), then an Ohio congressman who had also served as a major general in the Civil War. In this first of such annual addresses at Arlington National Cemetery, Garfield, who in 1881 would become the 20th president of the United States, sets a standard by explaining what Decoration Day is all about and why it should be commemorated.
An excerpt from Garfield’s address:
I love to believe that no heroic sacrifice is ever lost; that the characters of men are molded and inspired by what their fathers have done; that treasured up in American souls are all the unconscious influences of the great deeds of the Anglo-Saxon race, from Agincourt to Bunker Hill. It was such an influence that led a young Greek, two thousand years ago, when musing on the battle of Marathon, to exclaim, “the trophies of Miltiades will not let me sleep!” Could these men be silent in 1861; these, whose ancestors had felt the inspiration of battle on every field where civilization had fought in the last thousand years? Read their answer in this green turf. Each for himself gathered up the cherished purposes of life—its aims and ambitions, its dearest affections—and flung all, with life itself, into the scale of battle.
The book What So Proudly We Hail: The American Soul in Story, Speech, and Song (which George Will reviewed as “magnificent . . . a civic education in one volume”) is available here.