The mission had come down from William Tecumseh Sherman with characteristic bluntness: 'Those cars and locomotives should be destroyed if to do it costs you 500 men.' Major General Quincy A. Gillmore handed the job to Brigadier General Edward E. Potter, who took command of a 2,700-man provisional division at Georgetown on April 1. The objective was the railroads between Florence, Sumter, and Camden - the rolling stock that the retreating Confederacy had hidden in the South Carolina interior. The First Brigade was commanded by Colonel Philip P. Brown of the 157th New York, with detachments from the 56th New York, the 25th Ohio, and the 107th Ohio. The Second Brigade belonged to Colonel Edward Needles Hallowell of the 54th Massachusetts - the famous African American regiment that had bled at Fort Wagner two years earlier. With the 54th rode the 32nd and 102nd United States Colored Troops.

Confederate militiamen under Colonel James Fowler Pressley had thrown up meager earthworks at the millpond and settled in to wait. They had two working artillery pieces - a third was too rusted to fire. Lieutenant William Alexander McQueen commanded one. The other was crewed by Lieutenant Pamerya, a New Orleans artilleryman who was supposed to be recovering at Sumter hospital but had reported to the line anyway. The defenders were outnumbered and outgunned. Potter ordered Hallowell to swing left and rear with the United States Colored Troops, the 54th Massachusetts among them. The flanking column could not reach the Confederate position, and countermarched back to the main road. Hallowell's brigade arrived around two in the afternoon.

When the assault finally came, Lieutenant Pamerya was killed almost immediately - a Minie ball took him in the forehead. Lieutenant McQueen went down with a shoulder wound. With both artillery officers out, the Confederate line buckled. Pressley's men fell back toward Sumterville, made one more stand, and left the field about six in the evening. Southern losses: six killed, seven wounded, two captured. Northern losses: four killed, twenty-three wounded. Honest numbers from a small fight. A witness named W. H. Garland of Fernandina, Florida, would later claim that at least fifteen more Union dead lay where they had crossed the swamp, buried in shallow graves that camp followers later dug up and robbed. The same camp followers, he said, hanged Mr. Bee, an elderly Charleston gentleman who had fled to Sumter County for safety. His home stood near what is now Bee Street, east of Manning Avenue. These are the details that armies do not put in official reports.

After Dingle's Mill, the Confederate force simply disbanded. Most of the militia were local men; they walked home. The Confederate cause as a national project had collapsed the same day at Appomattox, but news traveled only as fast as a rider or a wire, and there was no wire between Virginia and Sumter. The war kept being fought in South Carolina for nearly two more weeks. Nine days later, on April 18, Potter's column reached Boykin's Mill, where the last Union officer of the war would die at the hands of a fourteen-year-old. Today the site at Dingle's Mill is marked by a roadside historical marker. The mill pond remains. So does the road. The men who fought here, North and South, were among the very last to do so - their fight a small, sharp, sad coda to a national catastrophe that had, in the strict sense, already ended.