By the fall of 1864, the Tennessee River was the Union's critical supply artery into the heart of the western theater. Supplies flowed upriver to the depot at Johnsonville, where they were offloaded onto rail cars and shipped to Nashville, feeding Maj. Gen. George H. Thomas's Army of the Cumberland. The stakes were enormous. Confederate Gen. John Bell Hood was marching his army through northern Alabama toward an invasion of Tennessee, while William T. Sherman -- having chased Hood as far as Gaylesville, Alabama, then given up the pursuit -- was preparing to turn his army east for his March to the Sea through Georgia. Sherman left Thomas to defend Tennessee with whatever forces he could assemble. Every barrel of hardtack, every crate of ammunition arriving at Johnsonville mattered. Lt. Gen. Richard Taylor saw the opportunity and ordered Forrest on a wide-ranging cavalry raid to sever the supply line.

Forrest began his raid on October 16, 1864, though his men were so exhausted from a previous campaign that he gave them orders to scatter, find fresh horses, and rejoin later. By October 28, he had reached Fort Heiman on the Tennessee River north of Johnsonville and emplaced artillery along the bank. Over the next two days, Confederate guns captured the steamers Mazeppa, Anna, and Venus, along with the gunboat Undine. Union river traffic to Johnsonville stopped cold. Forrest, ever the improviser, repaired two of the captured vessels and pressed them into Confederate service. On November 1, his unlikely flotilla set out alongside his overland cavalry. The experiment was short-lived. Union gunboats challenged the makeshift fleet on November 2, forcing Venus aground. Six more Federal gunboats arrived from Paducah, Kentucky, and by November 3 they were trading artillery fire with Confederate batteries on Reynoldsburg Island. Forrest's naval adventure was collapsing, but it had served its purpose -- the Union fleet was occupied while he positioned his real weapon: Capt. John Morton's artillery batteries.

On the evening of November 3, Morton positioned his guns on the west bank of the Tennessee, directly across from the Johnsonville supply base. The next morning, what remained of the Confederate flotilla was destroyed -- Capt. Frank Gracey, a former steamboat captain turned cavalryman, set Undine ablaze rather than let her be recaptured. But the land batteries proved devastating. Morton's guns pounded the wharf, the warehouses, and the twenty-eight steamboats and barges crowded along the bank. Three Union gunboats -- Key West, Tawah, and Elfin -- were disabled or destroyed. The Union garrison commander, fearing capture, ordered his own supply vessels burned. The fires merged into an inferno. Forrest himself recorded the scene: "By night the wharf for nearly one mile up and down the river presented one solid sheet of flame." He withdrew his command six miles that evening, navigating by the glow of the enemy's burning property.

Forrest's damage report was staggering: four gunboats, fourteen transports, twenty barges, twenty-six pieces of artillery, one hundred fifty prisoners, and property valued at $6.7 million -- a figure one Union officer disputed, putting it closer to $2.2 million. Either way, Forrest's own losses were almost absurdly small: two men killed and nine wounded. The raid shook the Union high command and intensified concerns about Sherman's plan to abandon the pursuit of Hood and march through Georgia. Forrest's men slogged through heavy rains to Perryville, Tennessee, then on to Corinth, Mississippi, arriving November 10. Confederate theater commander P.G.T. Beauregard then assigned Forrest's cavalry to Hood's Army of Tennessee for the Franklin-Nashville Campaign. Hood delayed his advance until Forrest joined him on November 16 -- a wait that gave Thomas precious time to prepare the defenses that would crush Hood's army at the Battle of Nashville the following month, effectively ending the war in the western theater.

Today, much of the Johnsonville battlefield lies beneath the southern reaches of Kentucky Lake, a vast reservoir created in 1944 when the Tennessee Valley Authority dammed the Tennessee River for flood control. The wharf where twenty-eight boats burned, the ridgeline where Morton placed his guns, the channel where Undine exploded -- portions of this landscape are now navigable water, visited by fishing boats and pleasure craft rather than gunboats. What remains above the surface is preserved across two Tennessee state parks: Nathan Bedford Forrest State Park on the Benton County side and Johnsonville State Historic Park on the Humphreys County side. The American Battlefield Trust and its partners have acquired and preserved additional acreage. Standing on the bluffs above the lake, you can still trace the curve of the river where a cavalry general played admiral for four days and set a mile of the Union war effort on fire.