This poem was published in a volume of Autograph Leaves sold at the Baltimore Sanitary Fair 19 Apr 1864 (Patriot's Day). Lt. Col. Alexander Bliss (step-son of George Bancroft) collected--with his father's help-- numerous samples of writing written and signed by American authors to be sold in a limited edition volume. As Wachtell and Norsworthy discuss, a corrected version of the Fredericksburg poem intended for this volume was sent to Bliss on 22 Mar 1864, but Melville's corrections didn't get printed. The corrections came a few days after the initial version was sent--we can't be sure how many. We may reasonably suspect Melville's earlier contribution had already been delivered to the printer and could neither be altered nor suppressed.
Melville's corrected version appears at the head of this note. The corrections were slight--a word change in the title ('Slain' becomes 'Dead'), a word added to the opening line ('glory' becomes 'dreadful glory'), a spelling variant in the final line ('strown' becomes 'strewn'), along with emendations to punctuation and layout.
Wachtell focuses on the opening of the poem to conclude that Melville "subtly alters and challenges the otherwise reverential tone" of the poem. She casts the changes as a compromise between "comforting romanticism" and "discomforting realism."
Even though the season was off by a few months, the Passion imagery in the poem emerges from a natural event. On 13 Dec 1862, the battlefield of Marye's Heights was illuminated for 20 minutes by an Aurora Borealis, There was enough light that soldiers closest to the enemy could move about stealthily and tend to some of their wounded comrades. (See for example J.L. Chamberlain, The Passing of the Armies.) The soldiers who marched dutifully to their death up Marye's Height lay strewn across the battlefield while the aurora played across the winter sky.
In my judgment, the changes are in the nature of refinement rather than reversal. Use of the word 'Slain' invokes a slayer and a slaying. Substitution of 'Dead' removes the natural path a mind might follow to assign blame and its neighbor, hatred. When the title change is made, the addition of 'dreadful' in the first line invokes the awe that 'Slain' contains and 'Dead' lacks. Replacing an aggressive noun in the title with a neutral noun, 'dreadful glory' is needed to encompass the entirety of a godhead who simultaneously inspires awe and adoration.
Wachtell asks the natural question: ""What about this [first] version of the poem did Melville find so 'wrong' that he wished it suppressed?" My question--less natural to ponder, I suppose--is "What does the language of his second letter tell us about Melville's internal mental processes?" Does the language he uses in his correspondence indicate any unusual anxiety or emotional distress over these seemingly minor changes?
Melville likely wanted to distance the poem from political criticism of the day.
A side note of interest is that Autograph Leaves spawned two of the five handwritten copies of Lincoln's Gettysburg Address. George Bancroft got a copy from the President in late Feb 1864 to send to his son, but it was written on two sides of a single sheet of paper and didn't meet the print requirements. Bancroft got a second copy to Bliss not long after, which turns out to be the only copy of this famous speech actually signed by Lincoln.
The first poem listed by John shows loses the starry image, but retains an uplifting theme. In three successive poems, Melville offers epitaphs inspired by the heavenly virtues. We met Faith when the tidings from the front were delivered to the Soldier's widow in "An Epitaph." "Inscription for Marye's Heights, Fredericksburg" serves as an emblem of Hope. Charity shows up next represented by "A Mound by the Lake."
Federal troops made challenging uphill assaults throughout the war, most with devastating results. A few that come to mind: Kennesaw, Lookout Mountain, Missionary Ridge, Chickasaw Bluffs, Vicksburg, Petersburg, Cold Harbor. The best line from the Autograph Leaves
poem shows up as the final line in "Chattanooga" (a poem focused on Army of the Cumberland's spontaneous ascent of Missionary Ridge).