“Chattanooga” comes from the same Cincinnati Gazette report that Melville adapted “Look-Out Mountain” from. The battles were fought on successive days and were in a sense aspects of the same contest. The most convincing evidence that Melville again used the Gazette occurs in his long note to “Chattanooga,” in which he speaks of an “account at hand,” which he is using. In this note he describes the weather the day of the battle in these terms: “Although the month was November, the day was in character an October one—cool, clear, bright, intoxicatingly invigorating; one of those days peculiar to the ripest hours of our American autumn.” Quite possible Melville had the following observation from the Gazette “at hand” when he described the weather: “The morning was raw and cold, but the sun shone brilliantly from a cloudless sky. The prospect was beautiful in the extreme” (Doc. 232).

Elsewhere in his note Melville comments on the way in which the Union soldiers, after capturing the rifle pits at the base of Missionary Ridge, swept on in contradiction of their original orders to halt their advance at the base temporarily. Melville remarks that “But there and then it was that the army took the bit between its teeth, and ran away with the generals to the victory commemorated.” This event is mentioned several times in the many reports from participating officers, but the most vivid narration occurs in the Gazette story:

Through the woods concealing the rebel rifle-pits they charged, and burst like a torrent into and over the same, scattering the terrified rebels who occupied them like thistledown or chaff.
Here, according to original orders, our lines should have halted; but the men were no longer controllable (Doc. 233).

Melville says of Grant in stanza two, “But mastered nervousness intense/Alone such calmness wears,” an observation perhaps prompted by the Gazette’s picture of Grant as “a mild, quiet, unassuming man—the solid, sound, subtle, persevering, comprehensive Grant”(Doc. 233). Melville’s description of the rebel cannon firing down at their attackers—”The summit-cannon plunge their flame/Sheer down the primal wall”—has a probable source in the Gazette’s account of the Union assault: “Despite a plunging fire from the enemy’s artillery upon the crest, they entered the timbered portion near the summit” (Doc. 233).
Melville concludes “Chattanooga” with a lament for those who, “eager, ardent, earnest there— / Dropped into Death’s wide-open arms . . . .” The Gazette reporter, too, devoted a full column to a description of the dead and wounded, and in at least one detail the accounts concur. Melville speaks of

These last lines surely were inspired by the Gazette’s eulogy for the Northern dead:

The expression upon the faces of our own men who had fallen here, was most touching and remarkable, for not all the pains of dissolution had been able to drive from their features the smile of victory, or the placid look of contentment which always rests upon the countenance of him who feels his work well done . . . for it was plain as the sun at noonday, that these men had died, not only without mental agony, but that their last earthly feeling was one of calm contentment or triumphant joy (Doc. 235).