Some discussion a few months ago at Civil War Talk pushed back against the notion of the Federal gunboats having a decisive role at Milliken’s Bend. After all, they were firing blind, caused few casualties, and were there in a supporting role.

But I view their role in the battle as truly turning the tide. The Confederate assault overwhelmed the Union line on the first levee. As the Union line collapsed and tried to make a stand at the second (riverward) levee, with the Confederates on their heels, the gunboats opened up. This put a halt to the Confederate advance. True, the Rebs did not scamper back to the treeline or withdraw in fear – but their assault was stalled. Without the fire from the gunboats, their advance would have undoubtedly continued. And quite possibly, the entire Federal garrison would have been annihilated, for there was nowhere left for them to go.

Maj. Gen. John G. Walker (CSA) saw the gunboats as a deciding factor in stopping the Confederates’ momentum: “In the meantime the enemy’s gunboats (four in number) had taken position so as to rake the open space between the second levee and the river with grape and canister; and had our men succeeded in gaining this open space, the enemy, by retiring to the water’s edge, would have given their gunboats complete command of the position. Under such circumstances it would have been folly to have persisted in the attack.” Although the Yankees only had two gunboats present, it is likely that Walker mistook the smokestacks of the transport of the 23rd Iowa as another gunboat. Similarly, the smokestacks of another transport, the J.S. Pringle, which arrived to carry off the wounded, may have been thought to be a fourth gunboat.

Maj. Gen. Richard Taylor in his report to Lt. Gen. Edmund Kirby Smith saw the gunboats as halting the advance as well, though to him it was inexcusable: “On mounting the second levee in pursuit, our men came in sight of the gunboat and transports (mistaken by them for gunboats), and at once fell back, and could not be induced to cross the levee.” Taylor viewed McCulloch’s halt with disdain: “Unfortunately. I discovered too late that the officers and men of this division were possessed of a dread of gunboats such as pervaded our people at the commencement of the war.”

So while the gunboats themselves may not have caused that many casualties, they did play a decisive role in the Confederate’s decision to halt their assault.

Source: O.R. Ser. I Vol. 24 pt. 2, p. 459-60, 464.