They dropped like Flakes —

They dropped like Flakes —
They dropped like stars —
Like Petals from a Rose —
When suddenly across the June
A wind with fingers — goes —

They perished in the Seamless Grass —
No eye could find the place —
But God can summon every face
Of his Repealless — List.
                                                                      J409,  Fr545 (1863)  

At first the poem sounds like a children's song. It has the cadence and meter of a lullaby or common ballad and most of the key words are one-syllable concrete nouns. Something is falling softly and quietly, something like snowflakes, rose petals or shooting stars – seemingly something lovely and ephemeral. The only force we see is that of a June "wind with fingers" that ruffles the roses. But immediately into the second stanza the word "perished" banishes any such preconceptions. Something terrible has happened.
        During the Civil War, Dickinson wrote only a small percentage of her poems about it; this is one of them. The Battle of Gettysburg, a terrible three-day battle with 51,000 casualties, occurred in the same year as she wrote this poem. Dickinson would have read the news accounts with their lists of dead and wounded and even though the battle was an important Union victory, the mood upon first publication of casualties was somber. The Springfield Republican, the Massachusetts newspaper edited by the Dickinson family's dear friend Samuel Bowles, had this to say about the battle: 

Attack of the 1st Minnesota at Gettysburg, by Don Troiani

Our soldiers credit the rebels with the most unyielding and fearless courage in the late battles. Torn to pieces as they are, having lost 30,000 or 40,000 men in this last five days, they are not used up. … Their endurance, their desperation, their utter disregard of life is surely worthy of a better cause. [July 8, 1863  p2].

A couple of weeks later, Harper's Weekly published an unattributed poem in a decidedly triumphant tone. The first two stanzas follow:

Grandly the army wrought, on the murderous field of battle;
It has wiped the stain of defeat from every soldier's brow:
Mid the clash of steel on steel, and shouts, and the harsh death-rattle,
The Army of the Potomac has won a victory now!
Honor to ye brave men, from the battle wounded and gory!
Honor to ye brave men, whom the angel of death passed by!
Ages on ages hence shall others rehearse your story,
And pray that when duty calls like you they may live or die.   [7/18/1863, p.450]

Gettysburg Nat'l Military Park

In contrast to the clash and carnage of war and to the (understandable) chest-thumping of the victors, Dickinson's poem is all quietness and grace. Once the poem has been absorbed, however, this quietness has its own chill. It is like watching a movie battle with the sound turned off, the soldiers shot, bludgeoned, or bayonetted in silence, falling to the ground in silent slow motion. As in time-lapse photography, the scene fast forwards until the "Seamless Grass" covers much of the battlefield where dying soldiers once lay. Dickinson's vision offers the scope of time and one can wonder if she envisioned the thousands of acres of meadow and woods that now comprise the Gettysburg National Military Park.

Dickinson's similes all come from nature. She has used snow imagery before to symbolize purity; using it here suggests here that the soldiers are innocents falling together in a blizzard of death. Like falling stars their sacrifice shines brightly as they die, their shed blood red as the scattered petals of a rose. What she leaves out is any allusion to cause or outcome. War seems to be a fact of nature just as snow, meteoroids, and roses are. Life goes on, as does the grass – and Whitman's beautiful line where he considers grass to be "the beautiful uncut hair of graves" foreshadows Dickinson's tone.

 The last two lines don't seem organically tied to the rest of the poem. God can "summon" every soldier, and "summon" does double duty here meaning both 'recall' and 'call', as if the soldiers were lost. That clearly wasn't the case, although the spot where each soldier died would be impossible for mortals to note. And the function of the last line is unclear to me. God's list can't be repealed. Yes, but how does that relate to the fallen soldiers? Are there other lists that are repealed? I imagine newspaper lists are amended as better information is obtained, but their lists are of a completely different order and category than God's. 
        Perhaps Dickinson wanted a reassuring close to the poem. She may have intended it for acquaintances who lost a family member in the war and reckoned that the Seamless Grass wasn't quite enough for such a one. Or perhaps this is Dickinson's oblique way of saying that each fallen soldier can be summoned by God – regardless of flag.